Question: How resin rich or dry do you make your fin panels? Do you aim for a super tight glass lay up or do you make it resin ritch. I’ve only done a couple and the ones I’ve done I’ve pulled as much resin out as possible without ending up with air bubbles. Just wonder if I’m just making extra work and wasting cloth.
Resin rich. No corduroy noise when squeegee the cloth. And no bubbles
Techniques vary. Hard to discuss ratio without addressing technique. The one I use dictates the amount of resin poured and my cloth ratio is high because I do a lot of rolling. Here’s how I do a panel, there’s lots of ways to get the job done but my ritual that has morphed over time works for me:
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I have a table with plate glass on the top and just wax it lightly with paraffin before starting. I found it releases a lot easier than car wax.
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Make a square dam the size of the panel by sticking down foam strips just 1/2" wider than the width, same with the length.
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Cut all the cloth so it just fits inside the dam. This way there’s very little edge waste. I cut the glass onto a sheet of paper right off the roll and set it up next to the working area.
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Pour some resin on the glass and brush it to cover the area.
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Lay down four layers, squeegee some resin on top then roll until all layers are saturated and tight. Squeegee hard then spread the excess resin over the surface.
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Repeat (4 at a time) until you get to the end of your pre-cut glass and add only the amount of resin each time to get the job done. After the last layer just squeegee off the excess.
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Hotcoat, then let it sit for a day before pulling it up.
– Catalyzing is a whole subject in itself but my general rule is to use about 50-60% of the catalyst I’d use on a lam job. The heat generated by the panel thickness really speeds things up once it’s lammed. Also, I usually break it up into 2or3 batches and catalyze each as I go. If you have any jelling on the layer you’re working on then you’ve gone too hot.
Excellent summary thanks Gene. a few quick questions if I may…
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Do you wax with paraffin wax?
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The foam you use for a dam, is it PU foam?
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How do you stick the foam down? Glue or just masking tape?
Thanks again, I am going to try this method.
I use modelling clay to create dams. It’s very easy to get the shape you want and you can fix on the fly if needed. Of course once everything hardens, there will be clay stuck to the edges so that needs to be dealt with but other than that it works well for me.
neat idea thanks. I wouldn’t have known if that was resistant to poly resin, is it poly you use? I suppose if you build a dam just the once and leave it attached to glass, you can just make the same size fin panel next time, or do you have to throw the clay? I will have a look for some.
After struggling with my first two panels (bubbles everywhere), I am wondering if there is a better way, like a dammed or box system, and POUR the resin in over a stack of cloth, or maybe better, drop the cloth into a bath of resin, and weigh down with a large square of wood coated in wax paper, with a weight on the back. I haven’t seen anyone mention this type of idea, so I assume it is flawed!?
I have done the wax paper on the bottom as well as wax paper on the top with a weight on top. It worked well for me but be aware of curing resin temps.
Did it help with reducing bubbles? That’s the only reason I am considering such an idea
I felt that yes, it did help with bubbles. However, I still got a few bubbles due to the fact that once the wax paper goes on you can’t see underneath.
Ah thats another useful point, thanks! I need to find some wax, I have loads of old candles!
I do not know about PE resin as I have not worked with it for years, but clear polyethelyne plastic freezer zip lock type of bags do not bond with epoxy, and works better than waxpaper, and remains clear, and can even be reused.
Working bubbles from center to edge with the dry hard edge of my squeegee, with the plastic bag barrier allows one to achieve a higher fiber to resin ratio and the ability to see the bubbles and force them out, yielding a result some degree of closer to vaccuum bagging.
Thicker plastic does not stretch easily but the regular sandwich bags can and will if one applies too much pressure when epoxy has thickened too much.
thanks
I agree. I have used plain old plastic wrap on many fin layups as well as ding repairs. It’s my go-to poor man’s vac bag.
Balls! Bought a fibre glass roller, it has a lot of veins on it, horizontal fins. I rolled HARD! Did 20 6 oz lay ups, rolling every 3 or 4 pieces, keeping it quite dry (Reverb advice given on forum somewhere about that), it all seemed to be going really well, until next day when i peeled it off. 
There is some magic going on here, and I just ain’t a magician!!!
Helter, for your first fin panel lay-up I wouldn’t worry to much about those air bubbles. By the time you sand most of it off foiling, half the bubbles will go with it. Shape it, sand it and see what you’re left with. It’s still good practice and practice makes perfect…
That’s a good idea! Will do that. Still peeeeeed off i can’t get rid of bubbles though!
Will post my monstrosity
“Keeping it dry” is really the last thing you want to do, you might have interpreted that wrong from whoever said it, probably the source of your bubble problem. Rolling and/or squeegeeing tight so it isn’t so resin rich might be a better way of looking at it. Start with plenty of resin, the roller will bring the excess to the top.
The wrinkles showing from the plastic, wax paper, or whatever you used there is unnessasary. That’ll happen every time, and it’s messy . Just wax the glass, if the panel doesn’t pop off easy then you didn’t wax it enough. I use parrafin but most use car wax.
Thanks Gene. Reverb said it on another thread about fin panels, I don’t think I misinterpreted it, but I DO think it is probably advice which is not suited to such a beginner like me. Also he may have been advising people who are using tons of resin. Hard to know what “too much” is, but your post helped. Gonna give it another go as other Swayers have also said wax paper can cause various problems. Thanks.
PS I wondered if using colour might cheat around the bubbles, if I have any boards to do coloured fins on
Foam strips; ie the Zig-Zag peel and stick stuff like you get from FCS. Peel the shiny paper off and stick it. Gene’s method is the same way that I have done in the past. Not very often and by no means a master. I need lot’s of practice on my foiling. I have a piece of “Tempered” glass that came off an oversized end table. I put a light under it to check for bubbles after each batch is laid up. I’m assuming Gene that the roller you are speaking off is a “bubble buster” ?? Although I have used a white cotton throw away roller like Fiberglass Hawaii used to sell for rails.
I ordered True Ames glass on Bonzer runners. Beautiful, but after glossing the board, I see bubbles! Maybe I was being a bit hard on myself when trying to get 100% bubble free!