Good to have you back Paul. What’s TOPHAT? I thought he was a kite surfer.
What you’ve seen happen is dead right Greg.
You’re adding a fine layer of glass that covers the weave of the heavier glass below, and is then easier to fill with sanding resin after doing so…
That being said you are still adding the weight of a wetted out 2.3oz glass as opposed to more sanding coat resin if you were to just fill the heavier weave alone with that… So the 2 methods would off set each other somewhat, although I’m convinced the one with the added 2.3oz. glass would be ultimately stronger and at the very least, more pin hole free and thus more water tight…
Also the cost of using added 2.3 oz. cloth is probably cheaper in the long run judging by epoxy prices… It would at the very least save some of that precious liquid for another day…
Vacuum bagging can be easier with 2 people, but I’ve been doing it alone for the last 5 years, and it’s easy as long as everthing you need material wise and equipment wise are set out in front of you near by, and the equipment is in good working order…The only really hard part about doing it alone is sliding the board into the bag…Sometimes it goes easy, somtimes its a bit of a struggle…
I haven’t done a full hand lamination since 1985… But saying that ; They’re all hand lams, except fot the added step of you puting it in a bag when you’re done …You simply use slower curing epoxy hardener mixtures, then speed things up as you get better… Once you find a systematic approach to bagging and it works well a few times, you stick to it, or even improve efficiency each time, usually by applying new tricks learned from the last “pull”…
Most important vac bag tip: Take your time doing rail laps, put them in the bag after you’re satisfied the lap job is the best you can do, and then the rails should come out better than when hand laminated… Usually compressed tighter and bubble / wrinkle free, if done right…
I 've done inlay and reinforcing patch hand laminations with no vacuum, but with a nylon peel ply squeegee’d down on top of the fiberglass to pull out excess resin from the patch…
If a vac bag job goes wrong for some reason, the peel ply (if you use one) still pulls out excess resin from the laminate and smooths the weave somewhat, so no worries…Never had that happen though, touch wood…
Greg…If you’re serious about doing some board bagging in the future … Feel free to send me a PM, and I’ll help you the best I can…
P.S. I really try to build as light as I can, but due to the fact that we ride these kite-surfboards mostly without foot straps, a little weight isn’t such a bad thing… Light weight boards can be picked up by the high wind and waves, and if you fall,you find yourself on the water with a powered up kite and a board that’s merrily tumbling into shore…We are starting to wear leashes when near rocky areas, but that brings with it the added danger of slingshotting boards…
6 to 7 lbs, is a good weight for a solidly buit 5.5’ to 6.1’ board for what we do on them ,even more wouldn’t hurt if the winds are nukin’…
What about the Twill or Satin weave glass, wouldn’t these types of glass take up less resin in your sanding coat?
hi kiterider im inclined to believe it would have MORE pinholes
this is why. the 2 oz cloth is a closed weave… air traps behind easily due to the viscosity of the resin and no holes in the weave for air to escape. so there would more likely bubbles under the cloth between the weave of the glass underneath. then after you sand the cloth you then expose these holes. and this is exactly what i found when i did it on No3.
greg, i guess you will inspect the laminate with a magnyfying glass and report back the result. keen to hear how it gos and will happily eat my hat
the best seal you can get on an epoxy lam is after laminating you use a squeegee and 30 grams of 10 to 15% xylene thinned resin and squegee it hard into the lam. then brush on another fill coat, this will eliminate all pinholes. you can do this fill maybe an hour or two after lam. or after full cure
when using material like eps and other materials that can be easily water damaged, then a good seal is critical. more so than the extra layer of glass due to the fact that composites boards are plenty strong enough (snapwise) with just one layer of 4oz
thsi is what i imagined a top hat perhaps. dunno
Paul, hey. Forgot my manners. Welcome back. You make me think. I like that. For the most part. Ha.
good to be back! i . but i think the silly account is pretty well dead. possibly a good thing.
Yeah Paul, Nice to have the real you back…
I never had trouble with air or floating 2oz. cloth… but then I squeeze the hell out of the lam at 25hg.vac…
The only pins I’ve ever had when bagging the lam were from it being too dry…
So how were the results with this Greg?I have some 2oz glass and I’m thinking o using it over some 4 oz to reduce fill coat weight and add strength.
this is roughly how sabs di his 3.8 pound board. he used litest balsa that he cut from 4b2s on a bandsaw ( lots cheaper). then taped them together. they were about 4 to 5 mm thick. he fliped them over and sanded the wood with a orbital . he cut the outline exactly and then rebated an inch or so in around the edge of the skin about 1.5 mm deep . he heated the resin and layed it up by hand flat and then bagged the lam flat on a sheet of masonite with no bleeder or anything the lam was face up. the skin came out of the bag looking already hotcoated and finished. he fliped the skin and hand layed up the inner glass with 3 oz and heated west systems epoxy ( with a brush). baged both skins on at once. then trimed the edges and rolled the rail round. then he glassed the rail by hand with tape and the tape came flush with the deck and bottom lam as it was rebated so the the rail glass was flush. these can be done as cut laps. then a light scuff and blew a coat or polyurethane 2 pac with a gloss from the gun. the board was 3.8 on scales and he bounced on it up side down and could hold it outstretched with one hand. the board was a 6 3 or something like that size
inside and outside glass was single 3 oz and was reinforeced in damage areas and fin boxes . his fin system was home made and it shows how to make it on a thread somewhere it resembles 4way fin system
he experimented with fin thickness by using 5 minute epoxy and quick bagging blasa wood to plastic fins . reshaping them and then hand painting with resin
yeah so any excess resin is squeezed into the balsa wood and waterproofs it i guess. but he was doing these lams with mimimal resin . i recall it was about 70 grams for inner and 130 ish for outer. perhaps less
Do you know how the deck held up on that board paul?
Paul, I take your point about potentially more pin holes under the 2.3 oz for the reasons you mentioned. It took a while to get the bubbles out, particularly since I was using rail channels. But I’m not interested in using xylene. One stray thought: if the 2.3 oz does act as a barrier to resin flow due to the viscosity (you may well be right), then putting it under the 4 oz would have some benefit too. It would to some degree keep the resin from moving into the EPS. maybe.
Jesus, I am still tinkering. I have Xglass and want to pursue its use, but I can only get it in 6 oz, and that weight doesn’t fit well with my lam schedule. So I think 2.3 oz at 45 degrees is an interesting idea. It ought to add strength but of course I’ll never know. I have a another bamboo fish to build now, and I will be meticulous in weighing at every step. Just for the experiment, I will put 4 oz on the outside bottom and 2.3 oz on the deck and see what can be learned.