Hey Matt, you need to use a vacuum jar in line so that any resin that gets sucked up will end up inside the jar instead of being sucked directly into the pump. You will need a one liter jar with a two hole plug in the top. One hole connects to the vacuum pump, the other to the work piece. Excess resin will settle in the jar where it can just be tossed without gumming up your vacuum pump. You need to put some blocking inside the mold so that there isn't just a big void inside for the 14.7 PSI air pressure to work against. The vacuum will place about 60,000 pounds of force against the bottom of the table top. Your mold has to be able to handle this force or the table top, and maybe the mold, will fail to support the pressure. Say you have a 36" diameter hatch. That hatch has an area of about 1017 square inches. With a pressure differential of just 1 PSI you will not be able to pull that hatch open. If you are unlucky enough to be on the inside, where the hatch opens away from you, your body will be quite violently sucked through that hatch followed by your legs, head, and arms. Ouch!

Jessica and Matt, it was great meeting you both last week and I appreciate you took the time to chat. Your insight and advice on the sailboat market was also really valuable and affirming. I didn't realize the daggerboard case I seen caused you so much grief.... I made it back to the great lakes via Michigan (the hand) and laughed a couple times at the shape on the GPS. Thanks again, I'll probably follow a little closer now and would love if theres anyway I can stay in touch once I get serious about shopping. I might need a consultant to bounce the occasional question off.

@MJSailing

2 жыл бұрын

Thanks Jeff. Shoot us an email from our website any time. -Matt

If it were anybody else going through this build process I think that I'd be worried but this is a Matt & Jessica build, I doubt a Pizza wouldn't be perfect never mind something this important !! Stay Safe & Fair Winds !!

Run the plastic vacuum bag under the box taking the loading off the particle board.. That will make the particle board a straight table an the vacuum part is separate on top... I am sure you have it figured out by now but it is a suggestion..... You guys do a fine job figuring out things and do a QUALITY job on your boat build.

@ekaa.3189

2 жыл бұрын

Actually do one better, and make the under side bag follow the inside of the mold so there is no bridging. So from the inside out it would be bottom vacuum bag, mold, mold release, fiberglass layers, release cloth, batting felt, top vacuum bag. Obviously the bottom vacuum bag and top vacuum bags are taped to each other to create the seal. On your vacuum lines, run a bunch more, and to multiple areas. Put small holes in the last few feet of them, then wrap them with the batting felt. Run each line back to the catch tank.

@ekaa.3189

2 жыл бұрын

Another option you can do is vacuum to the mold edge. This is what I've always done. The mold has enough area beyond the fiberglass for the vacuum bag to be taped down to it, and not the table or whatever under it. Your mold didn't seam like the type where that could be done because it was made out of pieces.

@lancmac

2 жыл бұрын

@@ekaa.3189 Two thumbs up.... great

@jonaszmarek7217

2 жыл бұрын

Need to add some channels for vacuum to be pulled evenly across the whole piece, currently the vacuum will be much greater around the area where the tube is inside the bag.

@w8stral

2 жыл бұрын

@@jonaszmarek7217 Yup, first thing I saw, along with the obvious lack of a excess resin trap going to pump... assuming this piece is even structural.... Just pony up and buy prepreg as well.

Hi Guys, I've made the chip board for over 30yrs now. The normal laminate board you have has very little bend strength such as what would of been happening there in the vacuum. It's amazing how strong a force vacuum has over such a big area. I would highly recommend getting some 19mm or thicker flooring chip board. It is rated for these types of forces and a lot more dense. Good luck. :)

If you get a side arm (or filtering ) flask, and a stopper, you can use it to make a resin trap to protect your pump.

You also need to put folds around the part and at every transition point so it pulls tight at the base and no bridging I remember doing this when I built composite parts for military planes back in the day

@FiferSkipper

2 жыл бұрын

Excellent point... It is a great way to minimize bubbles and also to fill the fillet with strand.

Hey, Long time infuser here. The problem you had is quite normal when not using a system that has a catch can for that same purpose. When making infused parts what we do is have a PVC pipe that is sealed on both sides that has 3 fittings in your case you can have 2 since you wont need the 3rd for a gauge. the PVC has one fitting for the vacuum hose and one out that goes to the part itself so that when inevitably the resin gets sucked up the PVC will act as a catch can and not damage the pump, with the third fitting you can add a gauge and close the system to make sure that there are no leaks. infusing is fun but tedious process I'm sure by the time you see this you have already figured it out but good advice for other people trying this out. if anyone wants pictures of what I'm talking about I'm sure we can find a way to get pictures to clarify any doubts. Keep up the awesome work!

@reguerete3397

2 жыл бұрын

Also when doing molds we tend to use high density foam to create our molds as its stronger and holds well when in vacuum i know its not cheap and it has to get machined but way less chances for error when molding

Resin through the vac pump….Yup, it’s a pain in the whatsits and can really wreck the pump. Definitely a good idea to run from your bag to a ball tap, then a separator pot, then to the pump to catch any excess resin before it has a chance to get near the pump. The reason for the ball tap is so that you can shut it off and drain the separator if it gets too full and if you’ve got a perfect seal you can shut it off and give the pump a break. I’ll confess, I found that all out the hard way but it was so worth it once I’d got the setup working well. The final bit is to be really picky about keeping ALL of the kit squeaky clean with lots of acetone washes and using Petroleum jelly on any bit of plumbing that you want to come apart easily, saves loads of time and trouble. Cheers, R. 😎👍🍻

@davidfarning8246

2 жыл бұрын

A "vacuum resin catch pot" is the way to keep your pump healthy. Vacuum bagging is as much art as science.

Using large amounts of cloth will require a "Infused" peace. Also the way you have the vacuum machine connected is wrong. Connect the vacuum to a small air tank, then to the mould. Connect a vacuum guage to the far end and monitor the reading's. You need a Valve on main line to adjust vacuum. Start vacuum, set to 1-3 pounds, getting the bag to set properly. You need someone's experience in setting this up properly.

Couple of hints to help you further: Mold: never underestimate the force if vacuum. I would suggest building the mold by stacking melamine board on top of each other, that might be the simplest solution. Either finish the edges with tape, but even easier is self adhesive ptfe film. If possible, use the nylon reinforced version. This surface does not need any release agent, and is relatively durable. For this project I would envelop-bag it. Wherever there are changes in geometry, place a pleat. However, on a surface it can be done as well. Laying up: begin with a resin-rich layer of glass. Make sure you trap as little air as possible. Tricky inner corners can be filled with impregnated strands of fiber. This prevents line bubbles. Next layers, laminate carefully and nicely. Last layer: with 8 layers, I would not bother impregnating it. It will impregnate once vacuum is on. Leave a mixing cup with the first resin catalised, a layer of 1/4” or 6mm or so, so you can check curing progress. Vacuum materials: use peelply, perforated film with P3 perforation or equivalent, and enough bleeder. You want to keep an air passage. Perforeted film will allow to remove the bleeder without removing the peelply. This makes removing the peelply a LOT easier. It also regulates the amount of resin which stays in the part so you do not end up with dry areas. Vacuum film and sealant tape: be careful with resin contamination: wet materials do not stick. Vacuum hose: compressor hose does not work, it gets sucked flat. I usually use hard plastic hose. Do not place the hose on the part, it will leave an imprint. Extend a royal amount of bleeder beside the part, and end the hose there. There is no problem taping up the hose with the bag. Special connectors are handy, bit overrated. Some bleeder around the hose end prevents bag punctures. Vacuum pump. Oh dear. You ideally only want 50% vacuum for this technique. Your pump pulls near to 100% vacuum. Great for degassing or for airco installation, but not for this project. The pump hates air movement, and will spit oil. (It does not spit oil once it reaches full vacuum, which in bagging, it will never reach.) At this moment I build dry pumps with pressure switch, so it stops when the desired vacuum level has been reached. I am in Europe though. I also see you found out pumps do not like inhaling resin. A catch pot prevents this. A metal pipe with ends shut and 2 fittings on them is the simplest version. PVC might work, but a puddle of heating resin in pvc pipe will soften it to the point of failure. Good luck with your project. I have no idea in what stage you are atm. If you like any more info on vacuum or other stuff, feel free to contact me. Herman at polyestershoppen dot nl

@rogermartin9481

2 жыл бұрын

Yep, I guess 8’x2’, maybe 2300 square inches and at 15 lbs per sq inch, over 34,000 pounds of force on particle board. Good luck guys. Only seems obvious AFTER it goes wrong. Good on you and stick at it, from Australia.

@flyinggybe2113

2 жыл бұрын

Those are words of wisdom, hope you take them seriously! You need to add a vacuum regulator which are expensive, but McMaster-Carr offers a reasonably priced plastic body vacuum regulator which would be adequate for your needs. Low cost polyethylene hose works well for vacuum bagging. You should add a long enough hose run to the vacuum pump to move it far enough away from the bag to more easily hear and seal leaks.

I was amazed that the board had cracked. I wouldn't have thought of that. I have confidence that you were able to overcome that setback.

@w8stral

2 жыл бұрын

15psi per square inch is a gargantuan stress on that board. If the mold was solid instead of having voids he would have gotten away with it most likely.

hello, StarChaser and Ian Chapman are right you need a vacuum reserve to smothers the pump work . I use modified presure cooker (from the trash) and it is very cheap and easy to do. It is also usefull for other usage (degassing small resin inclusions, etc.) you should also have a plug under your work to avoid wrapping. 1 kg (abnout 2 pounds) of air pressure per square centimeter over the area of your wok on makes a tremondous effort. this force can be used to your adventage sometimes, a vacuum pump is a very useful tool. best regards to both of you

The part should be fine. As a half section that long it will twist 1/4” OK. Save yourself the stress and just hand lay up the other bits. 👍

Things go wrong, having sponsors help bridge those expensive mistakes and the boat as a whole. You sponsor today having the night sky for any particular date is a wonderful idea. Nice choice 👍. Late for this video, won’t tell you where we’ve been ( But did go to a seal sanctuary on the Helford river) Great interesting video, Cheers you two

@MJSailing

2 жыл бұрын

Oh my gosh, the Helford River, I am SO jealous!!! Hope you had a great time there, we really hope to get back one day.

I definitely wouldn't to be too concerned about 1/4 of an inch. The bearings will define the movement of the boards guys, will all be ok in the end. We can never underestimated the power of a vacuum, it will crush steel drums in an instant. Great video Matta and Jess enjoyed this one the most. Another good method is to completely bag the whole item to avoid the able cracking. Perimetre sealing sometimes better for infusion only and is generally on a mould flange. Ross

The way you are doing it is the way we did repairs and don’t forget the thermocouple to monitor the heat of the part don’t want to burn up the part plus we used prepreg cloth which had the resin already on it

Use pva release agent on top of the wax polish, add surfactants (washing up liquid) to the pva ,about four drops per half inch in a plastic cup, a one inch fine art brush and it’s one stroke per brush full, be careful not to make bubbles whilst mixing. For the peel ply I use nylon lining from a sewing shop. And for the breather I use kitchen paper towel rolled up. You can buy the clear plastic as a tube, it’s used to make plastic bags. I use 1/4” brass water fittings and put take on the plastic cut a X and push the fitting in and screw on a large washer and nut on to the inside. Never had a problem and a lot cheaper!

You’ve probably finished them all by now, but if you put a reservoir in the line, it will stop any resin getting into the vacuum pump

That is an ideal part for Infusion Save your wet lam x 4 you would Need to sort out the bag and Tooling you should also have Perforated film between the Fluffy and peel ply for the wet Lam. Good luck

I used to build composite spacecraft parts out of carbon fiber and fiberglass. I got quite concerned as I watched you put your vacuum hose into your bleeder ply. We put peel ply over the layup, then a ply or two of bleeder over that which extended will past the part, then a sheet of polyethylene (a couple of plies of kitchen wrap will do), leaving some bleeder outside the poly sheet. The breather would go over that, then the vacuum bag. You might want to invest in a vacuum bag fitting if you plan to do more of these. The idea is to avoid having the vacuum hose going directly into the bleed plies.

@w8stral

2 жыл бұрын

That and not putting said tube only on one end. Assuming they actually need the strength in said part to begin with.

Oh, I thought you were going to do vacuum infusion, where you suck the epoxy into the mold using a vacuum compressor. It looks more like you are using a vacuum clamping system. Somebody else suggested putting plastic underneath, and I think that would be a good idea.

You're young and tough, press on and stay positive to keep your momentum going, likely to be other problems with a build this complex. At least you're with a large group of supporters and some good advice will come along. Look forward to the final reward, sail away!

Pretty cool, Johnson! Really impressed with the modeling, planning, anticipating, and dry running before the actual product. I could feel the anguish as "things" start to happen. Right as the scene cut is where I personally would be expressing one loud, long expletive for stress relief! I'm expecting that those "things" aren't quite as bad as they might feel in the moment. So my fingers are crossed. So cruel of you, because now I have to wait until next week to find out! On a side note, your sponsor product is very cool. I'm definitely considering them for birthday gifts. I loved your wedding pics, btw. Very sweet couple.

@MJSailing

2 жыл бұрын

Crazy to think it was 17 years ago when those crazy kids got married!! 😲 And you'll have to cliffhang for a little longer, we're still working on solutions right now, haha.

@underadesk

2 жыл бұрын

Not only was the planning calm and collected. We stopped by during the glue up, and you can see he pulled his mask down right away to chat! Friendliest people around. Happy sailing MJ

Thank you for showing this process as in depth as you have. I will be using this method to repair my own boat.

If there’s one piece of your boat you want to be bulletproof, this is it. Looking good, looking good!.

I'm no expert, but I think you'll have better luck with a resin infusion setup. The forces would be considerably less and you will end up with a more dimensionally accurate and lighter part. You already have most of the stuff needed.

The old adage rings so true here! It was incredible, watching you measuring, measuring, measuring, and measuring yet again, before you were (almost) satisfied that you had an extremely level surface, then cutting and placing. PERFECTION in work standards!!! Great good luck with this incredible project!

So when i was building boats.. we ran the vacuum line to jam jars.. the vacuum would go into the jar.. and the jar would collect any exsess resin.. and the would prevent the pump getting resin in it.

Just one more obstacle to overcome! Keep up the great work guys! Always here to help!

Having experienced something similar what I did was create a wooden frame of 6x2 with legs dropping down every 600mm to create the totally level base and then used flooring grade plywood as the table. All of the seams were glassed and then I put the plastic over that. Worked a treat. Sure it’s a bit costly to build but I used that table for a lot of other things over the years

Sheesh will keep rolling along you guys got this!! Great episode!! 👍👍👌👌👏👏

@MJSailing

2 жыл бұрын

At least we always get to learn from our mistakes. 😉

@ThoughtfulWander

2 жыл бұрын

@@MJSailing yep always even from mine... typo "well" not will in op lol 🤦‍♂️🤣😂

Wow! What a drag. Thanks for keeping it REAL. Awesome episode!

Thats t tough break on the table, no pun intended. That looked like a partial board base. Maybe try with 3/4 plywood and attach some 2x4's to the bottom to reinforce. Also, I think you could build a 10 foot table by joining two sheets of plywood together. You might have to put down a layer of glass and resin to join to together and make sure the seam is sealed but I think that would do it.

when you are fairing larger areas, try using a 9" tsping trowel and apply the compounf likr drywall tapping. Also remember sanding sucks and sometimes adding two thin coats is faster than one thick coat and sanding. Look at some how to videos and you can develope a touch for it.

What you are attempting is extremely high tech and laborious. Don’t give up, you can and will beat this beast. A new table reinforced with two sheets of plywood not particle board, should give you a non-cracking table to work on with less chance of warping. Just a suggestion. Good luck and God Bless. 🐻🙏🇺🇸

God bless you and keep your chin up

Been watching you guys for 5 hours straight, I have a place on Chincoteague Island and just drove past Kent Island to my home in NOVA, this evening. I would love to check out your setup, and lend a hand, just so I can learn. When you get to the electronics/ HVAC (recommend MABRU) / solar install I can be helpful. Watching you guys maintain composure under pressure "pun intended" is amazing. I've been catamaran "stalking" for almost 18 months and have almost given up getting one, until I saw your channel. I also have some ideas on how to speed up the process and would be happy to sync on a call to discuss. Dagger boards take a very heavy load, so I love the fact that your attention to detail is OCD 10X!!! I have been talking with some guys developing carbon fiber racing equipment, it might be worth talking to them, as they just finished my full carbon fiber wheels for a very heavy and powerful car- Tesla Model S Plaid ~(1100 HP & 900+ FT/LBS of torque). They have done tons of carbon fiber reinforced polymer (CFRP) work and designed their wheels to exceed SAE J3204 (Aftermarket Composite Wheels Made of Matrix Material and Fiber Reinforcement Intended for Normal Highway Use - Test Procedures and Performance Requirements) They also do some work with Oakridge labs and could build components that you may not want to tackle. Their factory is east coast (Jasper GA) and I know the them pretty well and they seem to have mastered tailored fiber placement (TFP), combined with high-pressure resin infusion and engineering design analysis, hell if they can make a 17 pound wheel handle a ~7000 GVWR load then, a dagger board case would be a weekend project for them. They would probably enjoy the "free" press as well, as they are an emerging market player. I am cheering for you and would love to dump some stock and do the same project, but I want to see yours first to get an idea of scope, size and complexity. They are looking to expand outside wheels, and you guys could work a social media deal with them direct...Thoughts? I plan to do a factory tour when I pick up my wheels..... also "glass" that work table and you will be back in business!

I hope you guys are able to save that piece. If not I hope the lessons were worth it ;) If you haven't already come up with your own solution, one option could be to run a sheet of plastic underneath the mold. This will eliminate the pressure on the bench and also press the mold directly into your glass work. Cheers and thanks for another great video.

Might I suggest a catch can between the vacuum pump and the vacuum bag?

Ah... loved your wedding photos.

Great Video !

I appreciate you guys showing us the failures as well as the successes. Everything can't go perfectly, but it must be an especially hard setback to deal with when it's a piece/process that has already required so much investment in materials, time and effort to set up....

You guys are awesome

Feel your pain, hard way to learn how much power 15psi crushing force is over a large area. Since your trimming the bottom next time finish the bag on mold rather than the table or run the bag underneath with plenty of pleats or build the mold solid without the voids. Happens to the best of us I've cut up a and binned a fresh layup of 8meter Carbon spinnaker pole full of voids. You may find your part is still viable though all the best.

Just a thought about vacuuming resin - maybe something like a small centrifugal dust collector might catch the resin before it gets to the pump. Don't know if it will work, but might be worth a try.

As they say hindsight is 20/20 sorry for your troubles with the mold cracking. But it makes sense now the atmospheric pressure of 14.7 psi so that's great pushing down on the glass to force the resin out but not so good on the underside of your mold it's probably equivalent of parking a cement truck on the underside. Again I wouldn't have thought about it myself but now it makes perfect sense right the mold should only be the board thickness so the forces are only put on the thickness of the board. So sorry guys and I hope the the part is still usable. Stay safe and positive as usual and you will work it out.

Sometime I’d like to come help you out since I live nearby in Annapolis and work at the next marina to the north of you! Can’t wait to see me on the hull of fame!

You need to also use perforated release ply between the peelply and bleeder ply.

A for effort, thanks for sharing as I learned a lot.

Sorry about the set back. You two are amazing!

You should have an intermediate catch chamber between the vacuum pump and the job to catch the excess resin, also what is the advised vacuum, normally this is not full vacuum since you may boil the volatiles out of the resin. I have normally seen people using rubber sheet as the vacuum membrane

The cracking problem is caused by a cavity inside the part, between the part and the table. I think the problem may be your mold. Is it hollow? If so, it needs to be strong and completely sealed so you can vent the inside to the atmosphere. You can do this by drilling a hole or two through the table underneath it. The table is being forced up by atmospheric pressure into whatever cavity there is in the mold.

@rjcoady21

2 жыл бұрын

I did the rough math and that table was trying to hold ca 46,000lbs of force 😅

It’s not a failure, its a learning opportunity .......sure it’s a bit pricy, on an already very pricy build, but you will work thru it. And I’m sure you will figure our some use for the panel down the line....errbody %#@*$ up....you ain’t the first, nor the last....boats looking amazing and I love every episode

Maybe next time build a frame for the table to ease the stress loads Maybe 7" on centers but your using what particle board with finished surface Maybe think of something stronger like some ply underneath too what do I know about vacuum bagging done it alot of times even with mylar and carbon and Kevlar always good results I also duct tape all edges before the suck factor and never pay for a nice vacuum pump like yours we use rigid vacuum so we can toss it after use

Tragic. Really feel for you guys. Not my area of expertise but see you have received good advice from others. Good luck with next attempt.

This is not a statement on you guys, but so many people underestimate air pressure. "Oh, its just 5 PSI....... Well yeah but if you got that on a whole 4'x8' sheet that's 23k pounds of force! 😳😬

Also need breather cloth over the whole thing from dumdum to dumdum and cut corners of breather cloth and tape corners and vacuum fitting under the breather

On the other hand - if it didn't implode like Mythbuster's tank, you know you've got a really strong part ;) 10 tons per sqm is not a joke.

This might me one of those times when it would help to appeal to your audience for help. The dagger board case is a physically large object with many layers. Lots of places where an experienced eye would help. There must be people who work with fiberglass or carbon fiber that would be willing to lend a hand.

Hang in there

Bugger, you might have t make a foam plug up?🤙🏼🤙🏼🤙🏼🇦🇺

Looks like you only used peel ply, your want release film on top of your peel to slow resin pull. I usually use 3 layers and breather bleeder cloth. A part like your making, safer to pull vaccum at the edge/closer to your seal, not on the part itself.

You will want to use bleeder cloth, or batten. This will absorb the excess resin. I have a great deal of experience with composite manufacturing and repair, in the aviation field. If you would like to contact me, i would be happy to provide some advice. BTW, extend a flap of bleeder beyond the edge of the piece, this becomes your place to put the vacuum port.

@MJSailing

2 жыл бұрын

I'm not sure if we're just calling it by different names, but a breather cloth did go down over the case, and at 17:47 you can see Matt giving an explanation on it. 🙂

@markanderson9008

2 жыл бұрын

@@MJSailing yes i did see that, but i had already posted the comment.

@larrynolte9611

2 жыл бұрын

Same here layed up the harrier jump jet for the military

When your laminate is over saturated use a 2nd or even 3rd layer of breather cloth to absorb the excess resin. I have consistently gotten 38% resin to fiber without using infusion.

@glennimmortal

2 жыл бұрын

Great suggestion, did you wet out by brush/roller or spray I used a wet out machine years ago. if care is taken you can almost achieve autoclave results with just a vacuum bag.

@SteelDoesMyWill

2 жыл бұрын

@@glennimmortal just a roller and also a brush on small parts. I always mix up my resin as an equal weight to the cloth I am laminating, when you start with what would be a 50/50 resin/fiber content that would be normal for wet lay-up and you know that roughly 10 to 15% will be absorbed by the peel ply and breather cloth then you know you won't be over-saturating the cloth to begin with. You also don't want to go crazy with total volume and have a 'thermal event' inside the vac bag. You are correct, if you plan carefully you can get near auto-clave results which is more than adequate for cruising sailboats, we aren't building rockets.

Holy cliffhanger Batman. Worst case scenario if it isn't (wasn't seeing the videos are behind) usable as a daggerboard case you will probably still be able to use the material to make things like backing plates and brackets out of it etc.

Ouch! Sorry you had to experience that. Your going to need to put reinforcements across the bottom side just as you would to carry load. This time it’s lift or upward load instead of downward pressure.

well dang!

So sorry you guys! Looking forward to eh next episode to see what any fix might be. And I've been a member of the Dark Sky Association for years! Also, do you stay in touch with Grace and Bill from Calico Skies?

Great Job!!! Thank You…. :-)

Maybe vent your pump OUTSIDE the area you are working so you don't get an oil mist on materials....

check out Mads sailing life ...he made a rudder ... the advice just below is great vacuum bag the hole thing get a few y adaptors

What model vacuum pump are you using ?

Couldn't have seen that one coming. Sh*t happens. Life is just a series of mistakes, hopefully different ones next time. One of the best eps yet. Love seeing you guys doing fabrication.

@MJSailing

2 жыл бұрын

Glad you enjoyed the episode!! Not to spoil too much, but it might still be salvageable. 😉

@jaysparc

2 жыл бұрын

@@MJSailing I had to rebuild a daggerboard case on my Weta trimaran after meeting with some unfriendly rocks while sailing. It was not perfect at the end, but sometimes "good enough" is just that. Since the boards actually rest on bearings, as long as that shelf is square/true a little variation may not be the end of the world. You guys are inspirational. I watch a few different fab channels and you guys never cut corners, always do the best you can do. There may be more popular channels, but I appreciate craftsmanship (if you haven't seen Aladino at Sailing Magic Carpet check him out, a true artist) and you guys are right there with him.

One of the best sailing channels out there!

Dang!

Yeah, vacuum can exert huge amounts of pressure. Unfortunately, taping the cracks on the underside of the table won't help much as the vacuum will pull the air in through the sides of the chip board table top. The easiest way that I can think of to get around your issue is to bag the underside of the mould too. Use some of the tacky tape to get the vacuum bag to take up the shape of the mould cavity, and then seal the top layer of the vacuum bag to the bottom layer once you are ready to pull a vacuum. (Not sure if I am sufficiently describing what I am thinking). What I'm getting at is, exclude the table from the vacuum process. So the vacuum bagged sandwich should be: |- vacuum bag -|- mould MDF -|- layup -|- peel ply -|- breather layer -|- vacuum bag -| Hope that makes sense.... Cover the exposed vacuum bag that's covering the underside of the mould, while you are applying the layers of cloth, to avoid getting resin on it. It might also be a good idea to line the edges of the mould, that are in contact with the table, with some of the breather fleas so that the vacuum bag can wrap around the bottom edge of the mould without getting damaged by sharp edges.

Where is your pressure pot before the vacuum pup? Do you U have one??

I was surprised you did not have bottle inline to catch the resin.

@MJSailing

2 жыл бұрын

Not for the practice one (we weren't expecting that to happen), but we did have a catchment system for the big case. 🙂

Hope the first one works out and you get a solution for the next one.

15 pounds per square inch adds up pretty fast

Bummer. The forces from suction are enormous though. Will be interesting to see how you fix it.

I'd be tempted to make a concrete table. That will certainly not crack. And its cheap.

@MJSailing

2 жыл бұрын

There's a concrete pad next to the tent and I did bring it up as a possibility. 😂

@chet3louisiana558

2 жыл бұрын

@@MJSailing you might have to pour a thin hard coat of something to smooth it out and level the low spots but it will be 100% flat when you do.

A great Mold release is something super cheap that you can buy from home depot which is the bee's wax Yes the toilet gasket wax. It works great as mold release. And it works better than even Turtle Wax. Try it out.

@MJSailing

2 жыл бұрын

Matt used Turtle Wax on our practice mold because it was all we had at the time (lost shipment from Amazon), but on the big mold we placed on 5 layers of Rexco Partall Paste #2. 🙂

It's a bummer Max Cruise doesn't supply you the dagger board housings. If you figure about -10psi for an ok vacuum, the amount of total inward force on an flat area 2' x 8' (2304 sq inches) would be about 23000lbs.

@Tomm9y

2 жыл бұрын

Perhaps they they were quoting $$$ and it appeared easy to DIY.

👍👍👍👍👍

Did you guys have to build them because you were one of the early hulls? or is it something that would also send you?

@MJSailing

2 жыл бұрын

This is one of those items that Max Cruise offered to build for us, but we wanted to try it ourselves. 😃

I feel the pain I have done composites on aircraft for many years

I don’t think this is the way to vacuum mold parts. I think you are supposed to suck in the resin through the glass, not wetting out the glass first. When you have wetted out the glass by hand, why not just roll it with a fin roller? It’s very common to put gelcoat on to the mold first, and let it cure before you fiberglass it.

@JCrook1028

2 жыл бұрын

That was my thought as well. Why vacuum it at all? Gelcoat it and lay the glass up on top. Life on the Hulls comes to mind...

The others will be better. .. Cheers to you ..

Good Grief Charlie Brown. I would put a call into the design folks and let them know what's up. I'm certain they'll let you know if the mold is a pass/fail. Maybe they can advise what material you might use for the base to avoid a repeat of the cracking problem. Maybe you could use a thick polycarbonate base or a thick piece plexiglass as base. Can't wait to find out what you do differently to resolves the cracking problem. Good luck. Hoping and praying all turns out well in the rerun. Alan

@JCrook1028

2 жыл бұрын

I wonder why this piece didn't come from the factory to begin with.

@onenuttybuddy

2 жыл бұрын

@@JCrook1028 Is the piece that cracked just like all of the other materials used in the build. I think it is.?.

@JCrook1028

2 жыл бұрын

@@onenuttybuddy Well, the piece that cracked isn't even part of the boat. The base board they were using as a support for the boat piece is what cracked. But as it turns out my question was answered by them in another comment. Normally the factory would supply the piece they were trying to make but they chose to try molding it themselves. So, it's just a learning process for them and one they accepted the challenge of and the costs of failure on. They said that now with the added costs of the 2nd pump the savings on the part from buying vs making it are eaten so. But they do get to learn how from it so still a net gain for them.

@onenuttybuddy

2 жыл бұрын

@@JCrook1028 Thanks JC

some 2x4 stiffeners every 18" would probably fix that issue, screw from top into 2x4 every 8".

I was going to inquire if you had considered using carbon fiber in parts, not knowing much about it I looked it up and found this- "The effect of the anodic surface treatment of fiber surface chemistry was evaluated with a Physical Electronics PHI5400 X-ray photoelectron spectrometer fitted with a monochromatic aluminum x-ray source

👍

what a shame it cracked, hope you guys can fix it

that would have me saying pretty unsavory things for quite a while. though im pretty well aware we dont actually control much in life, these kinds of incidents always feel harder to accept simply because the board was supposed to perform, yes in hindsight maybe it was too long thus with more leverage so to speak, but yeah, thats hindsight. im sure next time will go smoothly!

Ooooooops ✨🌊💨⛵️🏝🌞✨

Didn't see that coming, ouch. Cheers

@MJSailing

2 жыл бұрын

Two seconds before it cracked we were celebrating a job well done, haha. We did not see that coming either.

You always put a resin catch between your pump and bag. I use a 4" PVC pipe. I personally would not vacuum bag that, don't really see the point.

You will figure it out.