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

General Composites Discussions Composites Talk
#1

Recent customers have been giving me some decently small highly detailed pieces to make in small production runs (5-15pc). I really enjoy infusion as my final part quality is just fantastic and flawless, but with these new pieces… I need the fiber to hold in the details as I work around the corners and edges.

A friend of mine gave me a can of Airtac 2 and told me it will make the detailed job really easy as the adhesive holds the fibers inplace as if I were doing the piece pre-preg.

The problem I’ve found is that I wax season the mold, then PVA (just like I always have). The adhesive works great, but as I manipulate the carbon into the details, the adhesive sticks to the PVA and pulls it off the mold.

My thoughts:

  1. Use more adhesive (not just a light mist)
    -Pro’s? The adhesive will stay wet longer as I lay the fiber
    -Con’s? I don’t want to use too much adhesive which may alter the aesthetics of the final composite piece

  2. Ditch the adhesive and hope for the best
    -Pro’s? PVA untouched
    -Con’s? Scrapped parts if I can’t get the fiber enough into the tight corners durring bagging

  3. Ditch the PVA
    -Pro’s? I can manipulate the carbon all I want with out pulling the PVA off
    -Con’s? I absolutely can’t have a part stick and PVA is my security blanket in that regard

Would a wet layup be better maybe?

Any and all thoughts, suggestions, and comments welcome.

-C

#2

Using just wax as release can work but it’s it’s very mold surface and resin dependent. Some combinations work o.k. and some do not.

You might consider stripping the wax out of the mold with polishing compound and moving a semi-permanent release system like Frekote. This system release much easier than just wax. You would still need to test system and some resins and molds surfaces do not work with semi-permanents.

I think trying to do a wet layup will be very difficult if the part is complex. Using too much spray adhesive can cause cosmetic issues. Trying to not use spray adhesive is dependent on the part shape.

#3

Wyowind,
I appreciate and value your input. I’ve seen Frekote used within the pre-preg operations, but didn’t think too much of it and never did the research on its properties. I’ll look into it, hopefully that is the solution!

Clear Poly is the customers resin of choice on these pieces. Mold is a simple Tooling Poly, Glass Mat, 6" flanges.

End product is 282 Plain Weave 3K.

I agree that too much adhesive would alter the aesthetics of the final product, and that isn’t an option.

I like the rapid production of Poly… I typically deal in Epoxy, but this customer insisted on Clear Poly and with it I can pull 2 pieces a day, no complaints on that, just need to lock in these details and find a way to hold the fiber into the tight corners.

-C

#4

The Frekote system should work fine. I would still test it on the flange though. You will need to strip the wax from the mold surface. I use the Frekote FMS mold sealer followed by the Frekote 770-nc release. You can get small quantities from Soller Composites.

#5

Wyowind,
Awesome! And you think I’ll be able to use the Airtac2 without disrupting the release properties of the Frekote?

-C

#6

Yes. You should test it first. :smiley: There are so many mold surface, release, resin, in-mold-coating combinations out there that everything should be tested. Not every combination plays nicely together. Change any one variable and you can go from success to failure. TEST! TEST! TEST!

#7

Wyowind,

I always test first, play later. It’s through testing that I’ve found the current problem I’m in, that the adhesive dries before I can fully get the carbon into the details and sharp corners.

I’m going to try to source some Frekote locally as to not have to wait on shipping… but none-the-less, I will test your method with that release along with the Airtac2. I hope this works… I’ll keep posting and once the test goes through, I’ll also post my results.

Thanks again!

-C

#8

Do you have a picture of the part, just to have an idea?

Airtac 2 usually works great, but if the part is really fiddly, indeed you might run out of working time and / or place to handle the fabric. I am not a great fan of using adhesive on the mould surface, for visual problems you might run into.

as for semi perm mould release: these usually work great. A good quality polyester mould should release well. if Frekote turns out to be a problem, also take a look at Zyvax, Ferrokote, Chemtrend or others.

A totally different option might be prepreg. Your moulds however should be able to handle the heat.

#9

KR Anderson has 770 aerosol and they are in Cali.

http://www.kranderson.com/shop/applications/Release-Agents

Their price is less than half of most other places on it as well.

#10

HeyBen,

Thank you kindly for the good reference and web link… I do appreciate it!

Looking on that site, I didn’t see a table describing their lettering assignment to the products, but common sense would lead me to believe that ending the description in “AE” stands for aerosol.

Correct me if I’m wrong, but the product you are referring to is:
FREKOTE 770NC AE part number: 83469 at a great price of: $8.33

If the above is correct, I’ll be placing the order first thing Monday morning and hopefully they have an express shipping available (although it is considered Haz-Mat, so it may need to go Ground Shipping only).

Never the less, I like the convenience of a spray release, as I’ve always sprayed my PVA. I hope this works out and the Airtac2 doesn’t disrupt the release properties of the 770.

Let me know if that was indeed the product you were referring to.

Thanks again guys for all your help, priceless! I’ll keep the findings up to date

-C

P.S.
Herman, the camera battery was dead so I put it on the charger… pictures to come soon, thank you for your interest!

#11

Yes, I ordered it recently and it is apparently AE = aerosol. Their descriptions are very lackluster.

I always spray my PVA as well. The finish is much better. But that is also the reason why I am going to semi-perms. I dislike the finish of PVA. No matter how well you spray it, the final finish isn’t as nice as I would like.

I didn’t spend all that time wet sanding and polishing the molds only to dull it with PVA and create more post work and final cost on parts.

#12

HeyBen,
Good call man, I’ll put my order in first thing Monday. I know what you mean about the PVA, it took me a long while to develop a technique in spraying that wouldn’t dull the final part too hard.

I’m sort of excited for this product to work, no more gun cleaning or late night compressor.

I manufacture aesthetic and structural automotive parts, but even the structural pieces need to look tip top… so every piece gets clear coated. The PVA dullness didn’t hurt me too bad as I sand the pieces anyway, but if this new product works well, it will save me time as I’ll be able to just polish the pieces that don’t see sunlight, rather than clearing. Thank you.

-C

#13

BTW, I don’t like the Frekote aerosol products. For one, I don’t want to get release in the wrong place. Two, you fumigate your working environment. Three, waste more product.

With Frekote 770-nc I just wipe it on and wipe if off. The wiping it off is one deviation that I make from the Frekote instructions. If you don’t wipe it off you will get streaks that are difficult to remove. If you are going to paint/clear-coat the products after molding then the streaks are not a problem. If you are using in-mold coats to eliminate the need to post finish the products then you want a streak free finish. Wipe it on and wipe it of greatly reduces streaks.

#14

WyoWind,
Thank you for you advise on this… I’ll probably order both versions of the 770 and experiment. I originated in the hotrod business and was/am a PPG Gold Certified Automotive Refinish Technician, so spraying has always been natural for me… never the less, I am always learning and the wipe down method may indeed workout better hands down.

-C

#15

PVA gun cleaning? What is this nonsense you speak of? :wink:

#16

HeyBen,

My order of Frekote finally came in, even though they were located in Cali, it still took a bit… but maybe it was more on their end of “processing the order” rather than the actual time of transit for shipping.

Regardless, I have “seasoned” one of my molds with the Aerosol as you recomended and that stuff is crazy. It sprays on really glossy and wet with minimal product, and just like the can says… 10 mins later its dull and dry. I did a few coats and although they say you can “buff” the dullness to a gloss if desired with a cotton cloth, I’m going to do the first test with it dull and see how it releases first.

So… I “seasoned” the mold and then did a Airtac2 test by spraying the adhesive, placing the carbon, then purposefully pulled the carbon and re-positioned it. The release doesn’t apear to have come up and once I infuse it (today or tomorrow) and it cures, the true test begins… will the part release after pulling up the carbon/Airtac2 and repositioning?

If it does… WOW, YOU SAVED ME!!!
If it doesn’t… oh well, on to the next test/trial, haha.

To be continued

-C

#17

Did you seal the mold with the Frekote FMS sealer prior to applying the release? The sealer can really make a difference is how well the mold releases, retains it’s release properties, and is some scenarios inhibits the chemical reactivity.

#18

WyoWind,

First thought… Crap. Well, we’ll see how well it releases once cured. Hopefully this isn’t one of those “hit yourself in the head” moments as one tries to work out of a sticky situation.

-C

#19

any word on how it turned out?

#20

RC51,
Updates and pictures to soon come… there was a bit of a hold up on this infusion, a customer came in waving a lot of money around expressing his need to jump to the front of my production line… being that this was a sample/test I had to put it on hold… hopefully I can infuse today.

Sorry to those who are awaiting results… As the only employee I can only do so much, haha. Lots of customers + lots of money + one employee = test infusions put on hold.

-C