When do you use spray adhesive and what kind to use?

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#1

I am curious about spray adhesive for laying down carbon fiber in a mold. Does it distort the finish? It seems like resin would not flow under the glue and cause dry spots?

Also, what kind of adhesive are people using? Is it something I can get locally or is a special type needed?

As always, thanks!

#2

I use spray adhesive anytime I have a mold with pieces that will not stay in place. For example, a mold with vertical sides where the cloth will fall and move I would use adhesive.

I currently use an adhesive called Epokz that is meant to bind with epoxy resins. I have to order it in cases, but they cost the same as standad 3M spray adhesive

#3

I use super77 for heavy duty and camy 373 for light stuff. I think its camy 373. Camie maybe…

#4

The key, no mater what you use, is that you lay down a fine mist. Don’t try and ‘paint’ the mould or you will have dry spots. And a fine mist over a large area holds better than a few heavy spots.

#5

Can you get the 3M 77 at Home Depot in the US or do you really need to go to a specialty store?

#6

Hmmm… HD might have it. If they dont I would think your local fabric/craft store should like Michaels or Jo Ann Fabric.

#7

Thanks, I don’t think I need it at the moment, but I may get some and experiment a little when I start making larger parts.

#8

I thought I remember seeing it at homedepot tho…

#9

Home depot, ace hardware, lowes, menards, etc. Any home improvement store and most hardware stores will carry 3M Super77. I always get it from Home Depot. It’s about 10 - 12 dollars depending on your region.

What ever you do, DO NOT buy it from fiberglast.com. They will rape you to the sum of $30. They are super over priced.

Cammie 373 can be purchased at some hardware stores. But its mostly a specialty item for hobiests.

#10

Walmart is a bit cheaper for the super 77. Make sure you use a fine mist. A little goes a long way and the cans are pricey.

#11

Also make sure you clean the spray tip with solvent. I hardly do and I’m usually upset when it spits lol.

#12

Don’t scrape it off while pointing at your face. And don’t laugh at the guy who does as the next day you will do it.

#13

Is Super 77 spray adhesive compatible with epoxy resins?

#14

I don’t think it is compatible with any resin if you get technical but it works fine when used in moderation. Just keep a good distance between the can and fabric for a nice light coat. I used it to kit up all the materials for the infusions I did in the MTI hose thread and you can see it creates no problems. Plus DDCompound used it on the surface in his video and it didn’t have a effect there either. There are better spray adhesives like Airtac2 and Econotac2 from Airtech. You can make an account and get it from Airtech like most do or if you like to just make a simple online purchase Noahs Marine has some.
https://www.airtechonline.com/
http://www.noahsboatbuilding.com/items.asp?Cc=Airtech&iTpStatus=0&Tp=&Bc=

#15

When I spray it I don’t spray directly onto the fabric or the mold. I spray over the fabric or the mold and let it settle onto the fabric. You’ll get much more even coats.

Basicaly don’t spray the fabric, let it rain over the fabric, (and that rain better be in a mist form).

#16

Anyone uses StayZ from Zyvak? Is it worth the extra price?

#17

I have seen hairspray used in the past. Keep meaning to try it myself but have not done so yet.

#18

I would not. I’ve seen hair spray used as a PVA meaning it creates a film that is not disolved by resin. Correct me if I’m wrong. The thickness might also have something to do with how its disolved. But I wouldnt try it hah.

#19

I tried using 3M Super77 just the other day. I applied a very light mist to the mold surface (a waxed mirror). The fabric adhered nicely. But after the infusion was complete, the mold surface of the part was very sticky, and still had the residue on it. The mirror surface also had the residue on it. There were tiny dry spots from where the 3M was in contact. I was using Adtech 820 epoxy resin, which may have something to do with it. I will not use it again, at least not with this resin system.

#20

Try another spray glue. I have seen many problems with 3M77 and Super77.

I would avoid spray glue on the mould surface anyhow. Why not using a gelcoat (epoxy or polyester based) and stick the fiber to that?