So am I correct in assuming that had you baby sat the bottom lamination and worked to get the wrinkles out of the cloth and the bag; things might have turned out better???
I dont think so. It was more of an issue that the cloth is so thick it doesn’t work like doing relief cuts on 4/6oz. I cant really see it being a good idea to wrap rails with this material in any sense. The amazon linked one specifically…Lam seems great otherwise and looks killer.
Also, that picture is the current lam. Wrinkles don’t matter much. I have the peel ply nice and thick breather cloth around the board so those wrinkles don’t matter.
You used a Roarockit VacuVin to pull air out of a surfboard-size vac bag? That’s determination.
Well why vaccum bag:
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to maintain the fiber on the support. Resin glue like epoxy don’t need pressure to glue.
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to evacuate air bubble trapped in composit
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to optimize resin/fiber ratio
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for one to three layers of thin (up to 6oz) glass fiber on a surfboard shape, no need vaccum (round corner and it’s good). May be for light density stiff fiber you can think vaccum but there is other way (glue first)
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light vaccum with peelply+perfply+bidim and a constant vaccum pump is a must for bubble free, a good hand lam is not so far…
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optimize resin/fiber ratio depend of forces laminate take. If it’s tensil lenghtwise fiber low ratio is optimize, use vaccum. If it’s bending stress, (buckling)… best ratio is higher, need resin in, so vaccum can become counter productive for strengh, even more if you need to be waterproof. Key rule: resin elongation to break always higher than fiber one.
Industrialy vaccum bagging process is a complex process that need to be calculate, main problem is draining resin, we use it a lot with prepeg or infusion because need to warm molded thicker laminate.
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No, the biggest I’ve done is a full snowboard layup at 158cm.
Always use a shop vac over the wine tap to pull the bulk of the air out first though.
The idea is not to reinvent the wheel per say but perhaps optimize its spokes
Thanks Lemat for the insights!! In my case, I’ve just used the DIY Roarokit to make fins and now I’ll try with wood veneer over foam. I hope it works. But I don’t know how to manually stay around the psi that said stonburner.
You can make a switch. Know for wood i lamiate both side first, let cured, sand then glue wood with epoxy+cabosil, then lam over. More steps but that way you can use lot of pressure without problems and you have a seal layer between wood and foam that avoid water in wood if you have a water intake from fin plugs or ding rail.
Yeah honestly on a cloth that may be hard to wrap and get the wrinkles out of, the Jimmy Lewis “poor man’s vac” and baby sitting would be the way to go. UV Poly resin is also a good solution for troublesome relief cuts and laps. With UV you can keep working it. Once you think you’ve got it, run it outside and set it. If you run it outside real quick it won’t have time to pull away or fall off the rails etc. Usually you work to get everything right, looks good etc. You walk away from it and when you come back later the lap has pulled away and sets up. A trick I use is to take a 3 inch roller and roll resin around the bottom edge of the rail. I flip the cloth up out of the way, then flip it back down. Resin under the cloth makes a hanging lap stick. Works really well. Doing this helps keep the cloth stuck along the tail where those hard edges pull away and make those pesky bubbles along the tails hard edge.
The poor man’s vscuum bag it’s a good method, of course.
Lemat: I’ll try your method. You sealed the board before the first layer of glass?
Yes when shape is finished i seal both side and let fully cure then sand. After try many time all kind of process, without seal, lam on tacky seal, seal with net epoxy and all kind of spackle, i ended to the old, well known method: seal with epoxy “secret sauce” (ketchup consistancy) slurry and sand. You can do a far better composit skin, with best ratio for the purpose, when you lam fiber on a firm closed surface: resin stay where it need to be and you can spread it without deform shaped foam. Sealing eps foam is the most profitable way to waste your time.
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Excellent! I agree. Just a thin layer of secret sauce do the job. Thanks Lemat!!
Secret sauce as in acrylic concrete sealer?
No, that’s right there is many secret sauce in board build LOL.
Here is the eps foam sealer secret sauce:
50%epoxy + 50%micro + cabosil (up to whipped cream texture)= epoxy spackle.
You can also use waterbased lightweight homebuild spackle, the white one, cut with water for easy spreading texture.
This is all good info from lemat. Those new to board building should be taking notes.