Hi,
I use vinyl ester Dion 9100
and it doesnt cure properly.
The surface ofen remains tacky (but not in all cases)
If it seems properly cured, I apply on it a fabric with alcohol or aceton,
the surface then becomes tacky.
Alcohol and aceton melt the surface ! (but not fuel…)
After monthes of tests, I find no solution…
thank you everybody.
Most resins are “air inhibited”. That means the surface doesn’t cure completely. In most operations this is a good thing. It allows continuous lamination and a chemical bond. Do you need a hard surface? If so, you’ll need to add a curing agent. Old school is adding wax to the resin or spraying PVA over the surface before the resin cures. New school is one of many chemical surfacing agents that cure with the resin. Check with your supplier to see what they have.
thank you Roger,
I see what you mean,
but I dont think its this phenomena;
even when the surface is cured hard,
it goes tacky if wet with alcohol…
the vinlyester should “in theory” resist to alcohol…
I have some samples in fuel from weeks and they are still hard.
Maybe this vinyl ester dont cure properly because of accelerator or inhibitor add by the provider (just an idea…)
Someone who have a large experience with vinyl ester ?
I make motorcycle tanks and I need the good stuff,
its not possible to send to customer
a tank that become tacky with alcohol or aceton !!
I’m located in France, and interested in any solution, good provider, etc.
I t has been a burden to find the vinyl ester stuff and it does not work !!
Yes, well I have large experience with vinyl ester. About 62,000 lbs per year for about ten years.
Check with your supplier for a chemical resistant resin. Tell them what you intend to do with it. The resin companies have rafts of chemical engineers that are there to help.
Like usual , Roger is right about the resin being air inhibted. It can be hard yet not cured because of the air is prohibiting the surface from fully curing. Make a test laminate and finish it off with a layer of peel ply. The peel ply will inhibit the air from the surface and provide a cured surface unlike your previous laminates. Far as the resin being resistant to alcohol in some fuels you have to test,how long of a test, 6 months? Year? Alcohol free fuel you are fine with “most” ve resins.
Oh yea, Page 5 in the dion 9100 data sheet from manufacter addresses this issue …
ok Roger, I apologize…I am not an expert indeed.
Cheeky I read the page 5(was not in my translated doc it seems…),
I understand the wax parafin, its the same for polyester,
a layer to insulate from air, to allow drying.
-I can also paint it to solve the tack problem, isn it ?
-but when the surface is cured hard, is it normal to have the surface becoming tacky if a fabric with alcohol(or aceton) is applied on it ? the surface melt…
thank you all, you help is precious. I relly need to understand and solve this…
Hard does’t mean it’s cured, just hard. A layer of peel ply during the lamination, a coat of pva when it gels will work also. Yes paint would work , just not inside of tank.
Cheeky:
the surface remaining tacky is not the major problem,
as I understand it and know how to solve;
Also it only happen in some cases, not in all cases.
but as you said, “hard dont mean cured”, this is the point:
the hard surface(cured ?) becomes tacky if alcohol or aceton(but not with fuel) is applied on it ; the surface melt…
my fingerprint printed on such surface…its not just tacky.
for info I just introduced myself here:
http://www.compositescentral.com/showthread.php?p=60325#post60325
Again. . It’s not cured fully… add post curing to potential solutions to your problem.
seems Roger was right at first,
seems what melts is only the surface layer.
I guess the surface wich did not cure because of air,
in some cases becomes “hard”, but ready to melt if solvant comes.
I have sand the tacky surface,
apply solvant, no tack anymore.
We have experienced the same results with the 9100 system using a hand-lay technique. Although we have had varied results from different batches. Moving over to an infusion or vacuum process completely removes the tack problem on (tested with all batches we have received). The datasheet gives a kind of copout for the tack. If it was the same for all batches fair enough!