Hylomar sealants

[Robert Bondi]

Anyone used Hylomar sealants? I'd been assembling most of the gaskets in the intake area for vacuum stuff dry for years. My leak troubleshooting with the air compressor has revealed unexpected leaks that need mitigation. Big disadvantage of using silicone on everything is effectively gluing everything together and definitely forcing one-time use on the gaskets.

Small knicks and scratches over time probably make it harder to seal surfaces over repeated use and age. This Hylomar stuff claims to remain very pliable and good for repeated assembly/disassembly like race teams do, so it seems like a possible solution.

[onovakind67]

Hylomar is great stuff. I used it on some road race engines I built a few years ago. We were using a crankcase vacuum pump on these motors, and Hylomar is very effective at this type of sealing. It also is easy to disassemble the parts.

[Blaise]

Hylomar is great stuff. I used it on some road race engines I built a few years ago. We were using a crankcase vacuum pump on these motors, and Hylomar is very effective at this type of sealing. It also is easy to disassemble the parts.

BMW used to recommend Hylomar to seal the bases of our motorcycle cylinders. They always weep using Hylomar. Not ideal for THAT application.

[Mike W.]

I've heard of Hylomar, but never used it. I have had good luck with Permatex #3, the stuff that's applied with a brush. I wouldn't say it's really reusable, but at worst it does promote sealing and is easier to get off than when paper gaskets bond themselves to aluminum. Especially around things like water pumps and thermostats.

[Lenny D.]

+ 1 .

Works great on air-cooled engines as well.

[Tomcatdriver]

Hylomar is the best thing since sliced bread. It's perfect for the intake, water pump, thermostat housing, any oil sealing like on the timing chain cover etc. Very little goes a long way and seals VERY well.

[Jeff Dennis]

We used Hylomar on motorcycle engines for racing in superbike and vintage it worked well.