Opinions and uses of "Airtac 2" or any dry fiber adhesive for infusion

freekote FMS right?

https://tds.us.henkel.com/NA/UT/HNAUTTDS.nsf/web/02118965914E6EA8882571870000D9BC/$File/FREKFMS-EN.pdf

Ok I got the fms and release and tested it on my mold. Works good so I went ahead and infused a piece. I do have 2 questions though, 1. I was unable to buff the release and make it shiny, it was relatively smooth but had a dull look to it. And 2. When using adhesive spray is it absolutely essential you get every fold ad crack right? I mean the pressure of the vac pump also holds the fabric in place so is the spray adhesive used just to make it a little easier? Is it possible to infuse a part without the spray adhesive? Just wondering.

The adhesive is just to keep the fabric in place. I’m not sure what you’re molding but I’ve done extremely detailed intricate layups with very small step backs and doublers, compound angles, right angles, sharp corners, etc. With out the spray tac nothing would stay in place. And per normal layup, you can debulk the first and every fourth ply to make sure they’re all down and in the radius.

If it was a simple layuup you could in theory do it without tac. Maybe tape the edges in place? Spray tac just keeps everything down nice. Including the final layer of peel ply. It’s close to feeling like prepreg layup.

As far as every fold and crack… I try to use as little spray tac as is necessary. Especial on the first ply since it can show up, depending on the spray tac being used. And some types are much stronger holding than others, so less can be used.

ANd yah, freekote is kinda a pain for the buffing out. The instruction say to wipe on and then buff up… but it does get that frost on the surface, or haze. As long as the mold is very smooth and shiny, you should get a good part.

Thanks, what do you mean by “debulk”?

De-bulk also knows as compaction

It’s when you lay up one or more plys and then put on a vacuum bag in order to compact and consolidate the plys together. Helps to compact the plys and in when doing dry layup, adhere them together via the spray tack. That way they are nicely stuck when you continue on to later plys nothing will shift.

Nice! Ok I never thought of that but I bet that helps when you have many layers! Thanks, also how should I clean the mold for my next use?

yah, a debulk helps but, after the vacuum is released the fibers will spring back. So before infusing a good long time under vacuum is necessary to remove air and compress the fibers again.

For cleaning the molds… scrape any resin residue away with a plastic, wood, or composite scraper. Clean with IPA. Re-release if necessary.