permatex black silicone for seam seal?

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hi, so i'm new to welding and  i just finished tack welding a couple small patches in my engine bay of my 73 Vw camper and am wondering if i can get away with using Permatex Ultra Black Silicone to seal the seams?i do plan on painting the patches to match the rest of the paint job on the bus. the permatex packaging says that its good for up to 260*C and the patches aren't really that close to the engine.or is there something else i should use thats better?
Reply:The black silicone is great for a lot of applications, but this is not one of them. A much better product to use for this is professional autobody seam sealer. Look here: http://www.eastwood.com/ew-brush-on-...ler-quart.htmlThis is basically what is used by the manufacturer and virtually all professional body repair people.  The description is self explanatory.
Reply:You don't want to paint over silicone (unless it's the paintable kind, but Permatex Ultra Black isn't).Silicone dries too shiny and flexes too much for paint.You could use bondo, or better yet, a 2-part epoxy putty called Marine-Tex.  Either can be sanded down easily (unlike JBWeld).
Reply:thanks for your responses, now i know.
Reply:you can use paintable latex caulking in a pinch.tackleexperts.comwww.necessityjigs.comhttps://www.facebook.com/groups/mach...dingequipment/
Reply:Silicone rubber has acetic acid in it and can make metal rust and rot pretty badly.  Its a common problem with novices putting in auto windshields, the frames wind up rotting out.Use seam sealer.
Reply:Originally Posted by Drf255Silicone rubber has acetic acid in it
Reply:Might just go to a local auto paint shop.  They have seam sealer that is paintable.  I've used it on some trailers that I've built to seal out water on the tongue box.  Works great and doesn't dry out and crack from the Arizona heat.---No good deed goes unpunished---
Reply:Originally Posted by Drf255Silicone rubber has acetic acid in it and can make metal rust and rot pretty badly.  Its a common problem with novices putting in auto windshields, the frames wind up rotting out.Use seam sealer.