I need to seal up some cracks with some silicone, its says uv resistant and it will be on some lexan that seems to be doeing alright temperature wise down there , the silicones good to 400F, so i dont think it gets that hot near the mogul, do think im alright using the silicone?

Temperature-wise you should be OK. Might want to get some black stuff as the 'clear' will let a bit of light through

cool

Silicone II is suppoed to be good to 400ºF and has been used in many builds here. Wood burns at a similar temp so if the wood can take it so should the Silicone. I don't think it would be advisable in an enclosed light gate but anything with reasonable air flow should be fine.

I'd like to get some of that too. Is it readily available?

--- I looked at the "selection" at Wal*Mart, but none of them said anything like "high temp" on the tube, so I didn't get any. Should I go to Home Depot or Lowes instead?

More likely in an Auto Parts store

Auto Parts might not be a bad place to look but Silicone II is a standard product at HD and Lowes, probably Walmart and Target as well, check the back the instructions say to not use on items that will get above 400ºF which means that it is Ok to 400.

Auto store or good hardware store. Ask for Hi-temp RTV. Maybe a woodstove place would have something as well. There's also "silicone gasket maker" I think that would be fine too.

Yeah, I was thinking about getting some gasket maker. That would also be removable with some chemical right?

Once cured I think all those silicone-based products are pretty much totally inert so no you couldn't strip 'em off chemically just mechanically.

Really keep in mind what pagercam pointed out too - plain, old, vanilla silicone is pretty dang tough stuff.

I'm not sure if the paasket materials would be as good in non gasket jobs Silicone is more of a glue/rubber material, might need to try a few products to see what works best for what application. 400ºF should be good enough for almost anything inside a project don't really need to go higher.

In retrospect pagercam is absolutely right. Gasket-maker goop is likely quite a different formulation than standard caulking-type goop since they do different jobs. Might work, might not. Experimentation would be necessary.