Gas tank coatings.

RedBeemer · Feb 28, 2015

Took the tank off my 650SS last night and heard something inside. Put some light in there and I found the tank sealant I put on 25 or more years ago was pealing off in big chunks. That stuff is tough and I'll have to come up with some way to break the pieces down to fit through the filler neck.
What is the current thinking/process for cleaning and coating the inside of gas tanks? Have any products come along in the last quarter century that is an improvement to the plasticy goop that was there?

texasSlick · Feb 28, 2015

Aircraft stripper might dissolve the sealer inside your tank and make it easier to remove. Clean up any residue with MEK. You can kiss off the paint job with this recommendation.

Use the search function on this site to research new sealers.... there has been much written herein.

All good sealers require proper preparation, so if you go with a sealer, you will have to strip out and clean the tank interior scrupulously before any new sealer can be applied.

Slick

Beach · Feb 28, 2015

I prefer the no sealer approach on steel tanks...

texasSlick · Feb 28, 2015

Beach said:
I prefer the no sealer approach on steel tanks...

+1

Slick

RedBeemer · Feb 28, 2015

I prefer the no sealer approach on steel tanks...

That might not be a bad idea. When I got this bike back in '87 it had a fair amount of rust in the tank. I cleaned it, etched it and swished around the sealer (I forget what brand, but it set up like a hard plastic). It's held up for more than 25 years, so I can't complain too much but it is going to be a 'treat' to get out. Using stripper doesn't sound too good - as TS said, I can kiss my pain goodbye and I'm not going to do that. It has a really nice finish on it.
I'll see if I can find any recs here, but if you have used any thing lately, let me know good or bad.
Thanks

Horror · Mar 1, 2015

It's the Ethanol in petrol that's destroyed the sealer. You can get Petseal remover http://www.amazon.co.uk/Petseal-Solvent/dp/B006VB7FL4 , I think the chemical is Acetone. and will be cheaper to buy than a brand name. I try not to use sealer in a steel tank unless it's irreparable, I have fixed leaks without damaging the paintwork by using a 2 pack resin or instant metal on the outside of a tank. it's still there 28 years later. I recently had to seal my fibreglass tank as the Ethanol in petrol was desolving it. I used Caswell sealer which has worked well and is Ethanol proof. Another product that's been recommended is POR 15 tank sealer.

RedBeemer · Mar 1, 2015

I worked on the tank for awhile last night and it was "interesting"'. It appears that an area close to the filler must have come loose - perhaps there was some residual rust, whatever. This provided a spot for moisture to get under and spread, pushing the sealer off in large slabs. However those slabs are still tough as nails and hard to break or cut, especially thru the small opening in the filler. Once I finally get this out I am definately going to the 'no sealer' route and just minimize moisture in the tank any way I can. If anything, some kind of 'pickling agent' might be in order, ie, not a coating but rather a chemical treatment that reduces the tendency to rust.
An observation about coatings: this is just like dealing with other corrodable materials. I found using coating compounds for wood decks that are advertized to appeal to our 'lazy factor' to only need to be applied once and forgotten usually look worse and are actually much more labor intensive over time than using non coating type finishes that look great but need to be re-applied a couple times per year to work. The application of these type finishes is actually quite easy especially compared to dealing with flaking off coatings. Obviously the same holds here - much better to do a little maintenance periodically on the tank than have to deal with the horror show I've got now.

texasSlick · Mar 1, 2015

RedBeemer wrote:

"If anything, some kind of 'pickling agent' might be in order, ie, not a coating but rather a chemical treatment that reduces the tendency to rust."

A product called Metal Rescue removes rust, then "pickles" the steel to protect against future rust.

Slick

RedBeemer · Mar 1, 2015

Slick = thanks for that suggestion. I went on their website and it looks like the right stuff (after I get the other crap out). They even directly address motorcycle gas tanks. AND Frank Fritz from American Pickers recommends it :lol:
As to preventing further rust, they recommend another product afterward (Dry Coat) that sounds like a water displacement compound.

worntorn · Mar 1, 2015

In Canada, Chevron Supreme 93 octane has no ethanol, so I have been using it wherever possible thru the riding season. When it is time for winter storage, I make sure to fill the bikes with the Chevron stuff so that ethanol damage does not occur over the winter. With a full tank of ethanol free gasoline in there and some fuel stabilizer added, the lined tanks are holding up fine and the steel ones don't rust.

Glen

Beach · Mar 1, 2015

KBS might have a product to remove old sealer....I have done to a tank with good paint...I use plastic wrap and cover painted areas really well, sealing around filler with tape...I use product called Evaporust to remove rust inside tank and then just leave tank as is...Has worked so far on 3 tanks...

Jeandr · Mar 2, 2015

Horror said:
It's the Ethanol in petrol that's destroyed the sealer. You can get Petseal remover http://www.amazon.co.uk/Petseal-Solvent/dp/B006VB7FL4 , I think the chemical is Acetone. and will be cheaper to buy than a brand name. I try not to use sealer in a steel tank unless it's irreparable, I have fixed leaks without damaging the paintwork by using a 2 pack resin or instant metal on the outside of a tank. it's still there 28 years later. I recently had to seal my fibreglass tank as the Ethanol in petrol was desolving it. I used Caswell sealer which has worked well and is Ethanol proof. Another product that's been recommended is POR 15 tank sealer.

POR15 does not work! I have used Hirsch tank sealant http://www.hirschauto.com/Gas-Tank-Seal ... roducts/4/ in my fiberglass tanks with good results so far (3 years sitting still)

Jean

YellaPeril · Mar 18, 2015

I've found that Caswell Dragon Blood (2-part epoxy) tank coating works and is resistant to ethanol laced fuels. An untreated steel or aluminum alloy tank can and will eventually corrode if you are using an ethanol blend of fuel. The ethanol attracts water/moisture in the air. The water and air (as the fuel level drops) in the tank work to attack your tank inner walls and seams. Eventually, you are left with a rusty tank. The ethanol also dissolves the gel in vintage fiberglass tanks. I've used the Caswell product on both steel and fiberglass tanks with great success.

I have no affiliation with Caswell, just reporting my results. YMMV.