Log in

View Full Version : A caution about silicone sealant



Pierre B
04-22-2011, 08:27 PM
I have not seen this issue discussed much here on on the other Forum, but I posted something to this effect there quite some time ago. Here's the issue, and it deals only with possible effects of outgassed silicone on the raw, unpainted fiberglass body, if it is it is stored nearby (meaning in the same space).

Silicone outgasses as it cures,and as a result releases air-borne particles. If these deposit themselves on an unpainted body, fisheyes can result later where the bits of silicone prevent the paint from adhering. For that reason, I used urethane sealant to bond my aluminum panels, since there is no such issue with that material.

I learned this from my son (he and I built the car together). He had worked in Michigan and Connecticut for over three years in two high-end restoration shops, and the silicone shielding precaution was part of their protocol as well. Now not everyone is fussy enough to be concerned about this, but I didn't want to do anything during my build that could in any way compromise the paintwork later. Many builders do just fine, it seems, without paying attention to this possible problem, but I think it's worth consideration for those who might want to be extra careful. After the car body is painted, this is no longer an issue.

3kcarbon
04-22-2011, 09:49 PM
I've never used silicone sealants at a bodyshop but it is on my Mk 4. Good news is its been cured for months so lets hope its not a problem. I can say silicone sprays or lubricants with silicone in them is a absolute nightmare around wet paint. Even if its not on the the car. I have seen a car painted and drying but still wet have silicone land on the fresh paint and cause it to fisheye. I worked at a dealership many years ago that started having serious fisheye problems all of a sudden. Turned out one of the cleanup guys had it in for the painter. He was spraying silicone lubricants on the spray booth intake filters. Yes he got caught and was fired but only after causing serious problems in time money and materials.

efnfast
04-23-2011, 02:43 AM
My painter got to re-do my paint job days after he did it because of this issue - he didn't tell me about the issues with silicone, so when I was doing up my panels a lot of times I just placed the cocking gun right on the body, dripping silicone all over it. Lol.

Mark Dougherty
04-23-2011, 06:11 AM
Pierre
Thanks for the heads up on this issue. I am sure there are plenty of people that do not know not know of this issue.
Its been awhile. I hope all is well with you and yours
Later
Mark D

AC Bill
04-23-2011, 06:43 PM
That's also a reason why many body shops won't allow a car in the shop if it has had the interior treated with Armorall. The gassing off from it can contaminate other cars in the shop and cause all kinds of havoc..

rich grsc
04-23-2011, 07:19 PM
Once the silicone is cured, its not an issue.