[ame=“http://www.youtube.com/watch?v=BgD9oVw3GJw&NR=1”]YouTube - How to make carbon fiber parts[/ame]
Im guessing the guy is using 3m 77 adesihve spray?? does this help much and how many of you do this
cheers
[ame=“http://www.youtube.com/watch?v=BgD9oVw3GJw&NR=1”]YouTube - How to make carbon fiber parts[/ame]
Im guessing the guy is using 3m 77 adesihve spray?? does this help much and how many of you do this
cheers
ughh…PVA… Videos like these are enoying to watch sometimes.
I’ve used the spray and it’s handy for lightly keeping things together before you get the bag on. It’s kind of expensive though, at 10 bucks a can, and after watching skilling fabricators (20+ years experience) at a shop I got to visit, I realized its more of an aid than a necessity.
I don’t have that much experience though so I still use it whenever I just need that peel ply to stay still!
Yer i do stay away from pva. although i just been to pick up some glass and the guy at the shop said he used to use hair spray ?? i think il try some though.
Why is PVA bad? Whats the spray glue called?
3M Adhesive Spray. It’s sold at Lowes or Home Depot
I use either Airtac2 or Nautic Grip Infusion Tac.
With large structures you hardly get away with not using it.
Ive been wondering recently if the spray adhesive can create any issues with the bond between layers after infusion.
I try to keep spray adhesive to a minimum but it can be essential!
YES IT DOES!!! I forget what major issue is, and which resins. There is an infusion spray tac Herman mentioned, I think there is another few as well. They are meant to dissolve into the resin. I use VERY VERY little, just enough so the fabric stays, no heavy coats, and not over the entire piece. Even if it does create some issues, it’s better than spending 10x as long trying to get the layers to stay over a multi-curved surface…I also don’t use light weight fabrics
even the ones that are “made” for epoxies infusion are bad. They are all contanaments. If you look at the test sheets they will show that they preform better than spray 77 but compared to using none it has much lower properties. If you have to use it then just use a little in small areas.
I’ve used temporary hold spray adhesive (from the fabric store)in small quantity’s on the fabric cut line, to reduce the “frayed edge” factor. The parts I make aren’t going up in space or that critical, it does help with the unused roll ends in storage too.
Never thought of spraying contact cement to the entire piece of laminate fabric though, then applying it to a mold prepared with PVA. The contact cement would stick to the PVA, then tear/lift off the mold surface,(when making slight fabric fit adjustments) making everything stick. Wouldn’t you guys think a coat of some sort of “gel coat*” would reduce that problem,and allow a little buffer on the outside of the finished product?
For Nautic Grip I have a report by a university, where they did not find problems with inter laminar strength, when using NG-IF sparingly.
Anf that is also the whole point: using it sparingly. If you do it yourself, there is no problem. If your non-interested workers use it, you end up having problems. (and spending a lot on glue…)
non interested workers… ughh i hate those type.
I use super 77 3m glue and have had good results. Even when I spray on two coats. It all dissolves well if yo dont wait more than a few hours to infuse it. I wish I didnt have to use it, but I have no way to hold the fabric down into the tight corners and detailed edges. For example I make engine covers that have a sharp 90 degree angle. I have to spray the glue onto the fabric for it to sit tight in that corner. With out it the fabric would bridge and then I’d get a nasty looking brown corner from the collected resin.
Anybody have better ideas? I hate how sometimes the sticky fabric lifts the PVA and tears it leaving me having to start the project over again!
John
Ah, that is easy: Do not use PVA, but rely on the wax for release…
Or even better, semi permanent release
What does the PVA do thats so bad?
First its a extra step, not very production friendly . Second it creates a poor surface that requires post finish .
Ahh makes sense. The only time I get a good surface finish is when I spray on a flow coat of PVA after several mist coats. But that uses more… I’ll look into that permanent spray demolder :D.
Just make sure you get a sealer aswell as the release agent. Frekote is a good starting point