I can’t remember which thread I was going to post these pictures, so here they are on their own. I hope they help those of you thinking of bagging the glass on your boards.
the board is 6’1", eps core with 3mm balsa sandwich. Bottom has 2 under and 4 over with tail patch.
The deck has 4 under with 2x 4 + patch of 2 at ± 45.
Board with glass on ply fins but without 2 pac weighs 2.9 kg, (6lb).
First wet out bottom, flip, then deck.
Flip again and apply release film and breather to bottom, flip and do the same to deck, making sure they are really tight around the rails.
Next, slide into bag, slide perforated pipe into bag (attached one end to vac pump), seal bag and pull vac slowly, pulling all excess bag toward bottom of board (including pipe!). pull bag nice and tight around rails and corners.
The pipe allows even pressure throughout the bag without heavy breather cloth, picture 2 shows nice even bleed, except on the overlaps of the release film.
I have been debagging when laminate has gelled, but not fully hard, to allow a good bond with the sanding coat resin. In this photo you can see the wrinkles from the bag, but they are only resin.
This is the third board that I have done in this way, there have been small cosmetic blemishes and pinholes in all of them, bacause you do lose a bit of control when the bag goes on compared to a hand lam, but the resin glass ratio cannot be beaten.
This is just how I have been doing it, each time is slightly different, hopefully learning on the way!
If anyone has any better suggestions, please pitch in!
let me be the first to say this is very inspirational…
to get a good tight glass job in one full pass is incredible…
As usual a couple questions though if you don’t mind?
Resin/glass ratio? 1-1 in weight? Slow hardener?
How do you prevent the glass from delamming when you flip it over to apply the other side?
Do you wrap your perforated release film around the rails too? And if so by how much?
what was the work time it took to get everything in the bag? and didn’t it start to kick by time you started bagging it?
do you heat cure your lam during before or after this phase. They say you need 120-140F to set the epoxy correctly…
Thinking of doing mine with the regular cotton absorbant layer over the perforated release and then bubble wrap on both sides smooth side to the board instead of the perforated PVC pipe… See any problems going this way?
Thansk again great idea and great job…
You guys never cease to amaze me with your creativity…
I start out weighing the resin out at 1:1, then rely on breather to remove excess, I don’t weigh the consumables after, but guess at 60:40, glass:resin.
The glass does separate from the board, but just push it back, the vac does the rest.
I do wrap the rails with the release film, keep overlaps to a min, 10mm if you can.
Whole job, from start to finish takes about 1.5 hours, the SP 115 that I used has only standard hardener, but I mix small batches of resin, so have plenty of time.
I do put the board in an oven after, but only to 40 centigrade until resin has hardened, postcure is after sanding.
By all means use breather and bubble wrap, but keep them away from the rails and the ends, you will never get them smooth if you do.
Looks good. I have a question about the wrinkles. The top of my board turned out super smooth but the bottom had wrinkles (resin only) like yours. I sanded them out befor the hot coat, but it retrospect I was wondering if it would have been better to leave the wrinkles and hotcoat then sand the whole thing. How do you handle it? I can’t imagine not bagging the glass ever again!
Thanks for posting your pics. I lost my “bottle” (nerve) when it came to bagging the lam. Next time I will give it a shot.
I did some experiments with bubble wrap and did not like the fact that it left
the bubble texture in the laminate. Now I think about it the hot coat would cover it up. It did not occur to me that any creases would be resin rather than
glass and could be removed with a surform if necessary.
I pulled the bag flat, and kept tension on it until the vacuum was reached. The wrinkles come from the release film. Its very hard to get it perfectly flat since it wants to stick to the resin.
where you can pull the PerfRel taunt like wahoo says as you lay it over the wet glass.
uh-oh a brain fart just occurred…
any thought to wetting the glass on the PerfRel with some nonstick plastic underneath over a wetout table , then appling the glass/PerfRel to the board and peeling off the plastic? Seems do-able but like all my brain farts there’s gotta be something wrong with it… It seems too simple…
Almost like using prepreg just a wetter and sloppier version.
uh-oh another brain fart
jeez… what’s up?
how about doing the wet out thing then freezing it with a blast from a fire retardant CO2 bottle? It should stiffen things up and slow down the therm process giving you more work time and something closer to prepreg to apply…
What is the mold behind the table saw next to the dust collection system? The round one with red tooling gel coat? It looks like some of the radome molds I’ve made.
Yep, it is a raydome mould, think it came from oz,used to make the dome for ellen macarthur’s B&Q. ( just goes to show, must be more careful with the photos!!!)
I wonder if some of the bubble that occured on my hotcoat might have been caused by sanding out the wrinkles before it was coated? I was afraid they wouldn’t disappear but when I see how nicely your finishes turn out I can see the fear was unfounded.
This board is 6’1" x 19 /2, can’t remember the nose and tail at present. The deck is concave, with the thickness in the centre 2 1/8".
I am sure that the wooden fins help with the weight. Also, something that no one has mentioned to my knowledge is the density of balsa that is being used. The people that I buy mine from weigh every plank and sort them by weight. The deck is made of planks (1000 x 100 x 3 mm) weighing approx 65g and the bottom planks of 50g, they reckon that any lighter would be too soft. I would be interested to know what others are using.
This board has double the amount of glass that I used on my kneeboard, in a hope that the guy it is for doesn’t put his feet through it landing aerials!
Nicely done. Would you mind explaining how you did your rails? They turned out clean looking.
I’ve been thinking about laminating a perimeter balsa rail to a shaped blank, vacuuming the top and bottom veneer over the foam and perimeter rail, cleaning up the edges and laminating more perimeter balsa before final rail contouring.
What dimension balsa did you use? Did it bend OK or did you cut to fit?