And now surftech original pvc sandwich (=cobra windsurf tech) became a timber build maybe inspired by your timber boards and Greg timberflex. (And probably by margins too)…
Facts are your thread about vacuum boarded many swaylocks guys like me in compsand builds, never thank you enough for that.
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Thanks mate…
The thread in question was over 20 years ago…
Actually freaked me out at the time, coz in a few weeks it had like 50,000 views…
About a decade later I met another board builder, offline, in person, He made the statement …
It was the thread that started 1,000 vacuum pumps…
Back then, I honestly thought people all over the world must have been doing this, at the same time, it just felt like the next obvious progression, build them better, faster, lighter, stronger…
30 years in?
The Status Quo, hasn’t changed as much as I thought it would…
Oh 20 years! I understand why i have knee pain when i turn on the vac pump now LOL.
Lobbying, margins make the rules. Seems there are progress, i don’t hear no more that eps board are shit only pu boards are good…
Thanks for sharing that wealth of knowledge. Truelly a treasure trove.
@Bert_Burger it sounds like you did alot of experimenting in your time. Did you ever yse other fabrics than glass? If so what was your experience?
Follow this link and you can get the Burger process file with photos:
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Yea for sure…
Basically all fabrics work and offer something…
Synthetic fabrics are generally lighter as they suck less resin…
Natural fibers, tend to thicken up and suck a bit more resin…
Then each fabric will have certain finished properties…
The benefits with fiberglass is obviously clarity , quick easy wet out and doesn’t suck too much resin, especially compared to natural fibers…
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… and glass fiber are cheap easy to find in a variety of weight and fabrics style and have interesting middle class mechanical properties with stiffness and elongation to break that match easily with many kind of resin and others materials like wood panels.
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I’m pretty sure Gary Young was the guy that started vacuum bagging wood onto boards starting with wind surfers. He also patented the process. I think the way the Surftech boards were made is how the early windsurf boards were done in mold, not vacuum bagged. The core was shaped and then all the skin materials were placed in a mold with the foam in between then the mold closed for curing.
Here’s a video from how it’s made https://www.youtube.com/watch?v=SSZroHQblnQ
Going to try the flax cloth @sharkcountry linked on a 6’6 eggy twin with a blue PU US blanks.
Thinking 4oz/flax top and then just flax bottom. It seems very heavy duty. I was going to do 4/flax, 4/flax but I think the weight will be pretty high.
Also planning to vac bag. I was going to do the 4oz under the flax since it may be a drier lam. Thoughts?
Buy some flax and try to laminate it on a piece of foam… no need of vacuum bag for 4oz flax. Again except really thick laminate with many layers of low density fiber and/or hard edges shapes you don’t need vaccum bag lam. For monoloithic skins on foam that work mostly bending and need to be waterproof it’s mechanicaly counterproductive. Lost of thickness from compacting reduce more quadratic moment than increase Young modulus from higher density fiber ratio in bending work…
For lam flax (with epoxy): squegge some resin+cabosil past on foam, lay and glue flax on it, lam over avoiding to pool resin, roller is good for that. Final lam must look a bit dry, wet but dry LOL. Cheater coat when resin is on B stage, et voilà!
I would put glass over instead of cheater coat.
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I’ve only used Flax once on 5’ XPS foam pool board. I saw a post from Gary McNeil saying the flax on PU with a hand lam was heavy, so they were bagging it. They could hand lam with EPS.
If you know how to vacuum lam, I’d do it.
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Mechanically I understand not getting a ton of strength benefit,
but I’m worried more about weight getting too heavy with a hand lam.
Plus, I just like the cleanliness of the bagging process and less sanding overall
I have no problems with vaccum bag lam i do it often, when needed. Go for it.
I rolled the fabric back and wet the foam, then rolled the fabric back and wet out the top. Roll the other side back and do the same. Then I squeegee the heck out of the fabric to keep it as dry as possible.
It was an inlay, and I had already laminated the other side with a cut lap. Once I cut the fabric, I did a layer of 4 oz wrapping around the rails. I noticed that the fabric was very stiff when I prepared it for the 4 oz.
Great thread. I don’t know if worth, but I’ve done some tests laminating as normal but using cheap vaccum plastic bags (for clothe, travel, etc., a kind of DIY Roarokit) just for adhesión, without peel ply niether absorbent material, and is not bad. The resin layer you get it’s relatively smooth and thick enough.
Do you run the vacum continuously or just to get it to the pressure you want?
Going back to the OP’s first post. If you are after the ride and feel of a Poly board; start with a Poly blank. Glass that blank with Epoxy resin and Warp cloth(4 or 6oz.) in any combination. You would also (for additional $$) have the option of jumping to “S” cloth for added strength. It has been said many times and most in the Industry know that this is the strongest economical combination. No need to reinvent the wheel.
Just to get the presure. Nothing sofisticated. Just a wine air pump. If you see that need more pressure, more pumps…
The Roarockit system generates pressure close to 14 psi. Good for laminating wood veneers but a bit high for glassing.
At least according to Lemat and information I have seen elsewhere.
I’ve done plenty of vac bag lams with roarockit and composites at full pressue. Never had any issues with it.
I have some of this amazon flax cloth laid up in a bag as we speak. I did the bottom side and tried to wrap the rails…didnt’ work so well. Just the single layer of the fabric. Had to strip it from the rails but the lam looks good otherwise. Top layer will have a 4oz e cloth over it and the rails will be wrapped with the e cloth only.
