Friday, November 24, 2006

VW- More on Sealants

I've used ‘Ultra-copper’ on a lot of engines and liked it, except for the latex base. As a sealant it was better than Permatex since it formed a thinner seal, but as an assembly component I didn’t like the way it would sometimes peel off the case due to an accidental touch. Permatex would smear but there was always some left.

I started using the Loc-tite stuff because it not only formed the thinnest seal I’d ever seen (thinner is better when there’s no gasket), it was at least as tenacious as Permatex; you didn’t have to worry that an accidental touch would force you to clean & recoat the parting line.

But as I recall, the thinner for both Permatex and Ultra-copper was something so potent it made boy-mechanics give birth to two-headed motorcycles. I wouldn’t put Loc-tite on a bagle but otherwise it’s fairly benign; Hypolon has some trichloroethane, the other compounds are mostly silicones.

One note of caution, and the reason I’ve made this a general posting: If you’ve got to fix it and drive on, use Permatex. But if you’re building engines in the privacy of your own bedroom, with lots of time between assembly and test-running . . . at least 8 hours (more is better) . . . then use the newer sealants. They have a required cure time. The only guys I know who don’t like them are the types who never read labels; don’t give them a chance to do their job.

If you think about it, outfits like the Loc-tite Corporations are to be numbered among the Good Guys, white hats and all. They’ll never tell you red cars or faster or waste your time expounding on the virtues of 500 watt stereo systems in a bug. The value of what they sell is obvious. And if you’ve got some sexy sealing problem, they’ll usually offer some free advice on what might work.

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