Gas and oil resistant cauking???

[I Fish]

I've been researching this for a while now, and there is so much info, I think I'm even more confused, lol. I rebuilt the transom of my Sylvan a few years ago, and I did away with the splash well and built a motor well instead. I have a joint at the bottom that I caulked with 5200. The problem is, when filling my gas tank, I sometimes get the overflow/belch of gas back out the fill hole. This gas collects at the bottom of the motor well, on the 5200. I wipe it out, but, over time the gas causes the 5200 to lose adhesion, and it starts coming out of the joint.

So, I've been trying to figure out what type of caulking would work the best and still be gas and oil resistant. Anybody have a good suggestion.

 

[DeepBlue2010]

MarineTex will do the trick. You also can thicken some gelcoat with cabasil to past consistancy and fill the seem. Either way you choose, clean good with Acetone, clean some more and mask off where you dont want the filler to go. Best of luck to you

 

[Woodonglass]

This...http://www.ebay.com/itm/like/201367849514?lpid=82&chn=ps&ul_noapp=true

 

[I Fish]

Well, that's 2 answers that are way different, lol. I guess the questions with both products are how do they hold up in sunlight, and will they be affected by vibration? Remember, this is a motor well, and the joint is already made with rivets, so, this will be forced in like a caulk, with no further tightening of the joint.

 

[DeepBlue2010]

This...http://www.ebay.com/itm/like/2013678...&ul_noapp=true

This link leads to this product......







Which is very strange since the company who produced it has a totally different opinion about their own product

Here is what their datasheet says.. (This entire datasheet is attached for references) TheRightStuff_DataSheet.pdf




BUT, with the authority and affirmation you mentioned it ("This ....." ) I am sure that YOU know better!!! After all, when YOU say it, who gives a rat's behind what the company who made it says about it?!


On the other hand, here what Marinetex says about their product







In regards to UV protection, MarineTex says that you don't need any coating for UV or water protection.

 

[Woodonglass]

Please excuse me I Fish and DB 2010. I inadvertently copied the wrong link into the post. I think you'll find THIS Perrmatex Product will do the trick.

http://www.ebay.com/itm/Permatex-85...931b283&pid=100011&rk=1&rkt=3&sd=271839685724


Since your boat is an aluminum boat you wouldn't be using Cabosil and gelcoat to effect this type of repair. The MarineTex mentioned by DB 2010 will also do the job, Howeve, the area where you're doing the repair seems to me to lend itself more towards the use of the more viscous Permatex Product that will flow into the seam a bit better than the heavier bodied Marine Tex.

But this is just my opinion. Your boat your decision.