Needed a new gas tank for my 75 iron head sportster! It was modified years ago to acceptt a fat bob gas tank! I just ordered a set of tanks from J&P cycle and they recommend using a tank sealer! If the tank is Properly welded why would I need to use a sealer with a brand new tank? Any replies or suggestions are greatly appreciated! Are they just trying to cover their butt from a bad weld or am I thinking too far into this?

 

Get it and test it. (Plug the holes and dunk it in a bathtub, etc).

I don't see any point of lining it if its tight.

 

I wouldn't line it.

 

All replies are what I’m thinking! I’m going to fill them with water and let them sit for a couple days and if no moisture is found on the outside then I will drain and use a heat gun to get rid of the moisture residue! Cannot get around to it for another week and a half maybe two before I’m ready to bolt on so they will be well dried out by then! Thank you for the replies!

 

All tanks should be "sealed" which is actually a coating on the inside to prevent rust. I'm sure the factory ones are. I imagine custom unpainted tanks may be sold before that step.
I wouldn't use the cream/plastic type goop. Did that when I was young.
I did have good luck with a product that was very thin (almost like water) after cleaning the rust out of a tank. Unfortunately I don't remember the brand.

 

I use KB coatings tank sealer..used it many times,haven't had one problem.

 

will look into it! Thanks! New tanks arrived,got to trim a little off the lower front brackets but look like they are going to line up fine!

after trimmed the bottom will roll in a little neater!

 

I would clean the inside of that tank to get off any oil residue then coat it with Caswell's epoxy gas tank sealer.

If anyone tells you to use "Kreme" sealer, jimmy kick them.

You could also take your tank to a hot rod shop and have them coat it with Red Kote sealer. A couple of my bikes have that as well. The hot rod guys like to use it for older cars.

carl