OP827 wrote:Hi woodslanding!
I found that filling small voids with GS was not working great for me with more voids inside the GS after cure and it does not sand the same as foam.
It seems better to fill small voids before glassing with micro balloons and epoxy mix/slurry and right then lay the glass cloth similar to how Rutan moldless aircrafts were built.
I have not used GG in my build, I used PL Premium for wood and foam with good result, but clamping is needed as PL Premium, same as GG is expanding while curing from moisture in the air.
If you need to lay FG in tight corners around your windows you can brush epoxy and let it cure to be close to become non-sticky and then lay FG cloth in those areas. If FG does not stick you can carefully heat epoxy with a hairdryer or hot gun(carefully not to melt the foam) to make it sticky while warm again. Once surface is cooled but before fully cured you can then brush fresh epoxy on the glass cloth to laminate. Another known method is to use a very light spray single pass of 3M contact spray glue just to stick the cloth and then impregnate the cloth with epoxy, but I like the first method above better due to a full epoxy strength in the cloth with no contamination.
Hot wire will work on EPS and XPS foams, but will not work on GS polyurethane foam (and create poisonous fumes).
There is some good information in Moldless Composite Sandwich Aircraft Construction book by Burt Rutan.
These are all really great tips, thanks!
IIRC, you mentioned using dollar store wrapping paper as peel ply. Is this right? I'm trying to imagine transparent wrapping paper! Do you have any more details about that method? I like the idea of getting a good surface with peel ply, but haven't been able to find much on the web about using it with hand layup....
>>>EDIT: This stuff? https://www.amazon.com/Cellophane-100Ft ... 89&sr=8-18
and found this useful thread: https://www.boatdesign.net/threads/peel-ply.14461/
they suggest this: https://www.homedepot.com/p/3M-6-ft-x-9 ... /202975037<<<< That's pretty cheap!
I would think the foam has plenty of give, so I don't see the need to do foam work on the truck.... (I have done one test assembly to get the angle against the cab correct.)
Not so with the FG! Putting the FG on while mounted to the truck seems challenging (it's 4wd, and up high!) but I'm wondering about doing the first round of FG, and then moving it to the truck to let it cure. I'd think it would still have enough give at that point to sit flat.
thoughts?