I am going to vacuum bag a Carbon Fiber bar stool, using IN2 Resin, Soric and Carbon Fiber Tape at the edges of the Soric, like in the How To...Bonnet/Hood video. The stool will be like a 16-inch wide ribbon with a profile that looks like a "Z", and a Soric core. The total length is approximately 65-inches. I am in the US, and I cannot find Infusion Grade Spray Tack anywhere.

What method/s (other than Spray Tack) could I use to hold the Carbon Fiber Tape, Cloth, and Soric in place?

Many Thanks!

Unfortunately the Zyvax infusion spray tack is no longer manufactured. 

In order to hold these individual pieces of carbon on the mould’s surface we need to use some sort of spray tack, however, all of the spray tacks (including all of the so called infusion tacks) leave visible marks when used on the surface of the mould. This is because they are all designed for gelcoated or painted parts and not clear finish parts that are generally the norm for carbon fibre work. To overcome this, we do the following:

Invisible Epoxy Infusion Spray-Tack

1.    Start with a clean, small plastic ‘spritser’ bottle (any openable plastic bottle with a pump-action mister spray, like for hair-care products).
2.    Mix up 10g of infusion resin with 3g of infusion hardener and pour into the bottle.
3.    Add 10g of metholated spirits to the bottle (it must be purple meths, no white spirit, acetone, alcohol or anything else).
4.    Shake the bottle thoroughly.
5.    Spray a thin film of the spray tack over the surface of the mould.
6.    Allow the meths to evaporate and wait around an hour or two for the epoxy to start reacting when it will become particularly tacky.
7.    Stick your reinforcement to the tacky mould surface.

When you do the infusion, you will find that the tiny amount of spray-tack on the surface will cross-link with the resin of the infusion epoxy and become completely invisible with not even a trace of anything on the surface of your parts!

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

thanks for sharing that info, sounds good, will have to try that...all tack sprays do indeed leave something on the surface otherwise!

Matthieu Libeert
Founder MAT2 Composites X Sports
website: www.mat2composites.com

In case anyone is interested, I have recently switched from using the 3M Super 77 to using Cytec Aerofix 3 and am very happy with the results. I didn't have a problem with the 3M stuff, I found that if you applied it sparingly enough then it had very little impact on the surface finish of the part. That said, the Cytec stuff is perfect. It's made specifically for resin infusion, so there's no risk of delamination due to bonding issues and it sprays on blue so it's visible on the mould surface. Then when you infuse the resin, the spray adhesive polymerizes and goes clear so there's no sign of it anywhere. Works very well and I will be using it exclusively from now on.

Cytec Aerofix 3 is available from "www.ecfibreglasssupplies.co.uk" at around £12,-

http://www.ecfibreglasssupplies.co.uk/p-2961-aerofix-3-spray-adhesive.aspx


Unfortunately they will not ship anything to Denmark ...

I'll have to find a way to get it shipped here ...


The "homemade" spray tack is probably by far the most economical way, and not a problem if you have a production of larger parts running.
You can make up a batch of the spray tack, and use it up, then clean the bottle ...

When you're only making a few smaller parts a month/week, then the spray tack in a can is a lot more convenient...

I've used ordinary 3M spray on the intermediate layers, where it makes no diffference, since the spray tack is not seen, but I am a bit worried if it impairs the final strength of the laminate.

The "homemade spray tack" is a bit inconvenient here, since you need to leave it to cure to a tack...  which means hours between layers, and new batches of spray made up ...
(unless it works if you put the mixture in the freezer ??)




 


"Sapere Aude"... Dare to KNOW!

The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind...

103% of all people do not understand statistics...

Do not adjust our mind, theres a fault in reality :-)

I have a little improvement for you guys.

> 2.    Mix up 10g of infusion resin with 3g of infusion hardener and pour into the bottle.

Don't use the actual mixing ratio of the resin and hardener, use a ratio that is way off. Instead of 100:30 in this example, use 100:3 or 100:5. It's important that there is excess epoxy resin, NOT hardener. Without going into the chemical details, this converts normal resin into a sticky, gooey mess that can be stored for a long time (I have some samples that are several years old and haven't solidified) Such mixtures will thicken considerably but remain soluble since they haven't crosslinked. The large excess of resin in this case means the mixture also stays reactive, ready to react with other hardener molecules. This mixture will not go bad; once all the amine hardener molecules have reacted with their epoxy counterparts the curing stops and the mixture remains in its gooey state.
Dissolve this goo into a solvent and use it as your spray tack. Use sparingly, then there is no need to adjust the infusion resin mixing ratio. Your homemade spray tack will simply dissolve and disappear into the infusion resin, leaving no visible trace of its presence.

@brainfart  .

That sounds like it's worth a try ...



"Sapere Aude"... Dare to KNOW!

The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind...

103% of all people do not understand statistics...

Do not adjust our mind, theres a fault in reality :-)

All resins and hardeners are a little different, so even if I remembered the exact numbers I used in these experiments they might not work well for other resins. (I used regular laminating resins and a really slow hardener with a higher viscosity than infusion resins).

If anyone wants to try this out, take several small airtight screw cap glasses, put 10 grams of resin in each container, and then add 2, 4, 6 and 8% of hardener or whatever numbers you feel might work. Then leave the mixtures alone for at least a day, maybe longer. Since there is no exotherm the curing reaction will take much longer to complete. Check the samples for goo/tack factor by poking them with a stick. They should be nearly solid. Dissolve some in acetone and apply by spraying.

If for example the 6% works fine, more hardener can be added to the 2 and 4% experiments so they aren't wasted.

If anyone tries this out, please post your results.

Finally... Does anyone use it with success? If yes how much % hardener used and what disolve?

Just tried it but failed.
I dissolve it in acetone. I tried to spray it but unfortunately it was sprayed like a single beam. I couldnt achieve a mist. 
More acetone need? My mix viscocity was like syrup. Does it need lower viscocity... like water viscocity? Or my spray bottle wasn't appropriate? Thank you.