New Emgo tank- seal?

After a long and extensive study (45 seconds) of my fibreglass petrol tank I've purchased a new Emgo tank.
My painter is suggesting I seal the inside purely to prevent corrosion.
I'll pressure test it before painting but I'm not keen on the sealant idea.
Are these tanks ready to go or do they still require KBS/Caswells etc treatment
Thanks

Seal it with Caswell. It's only fifty bucks. You can't go wrong.
A rare opportunity with a brand new tank the prep is minimal and no paint job to worry about.

Although Caswell is a great product, you don't really need it with a new steel tank. A little rust won't hurt anything and certainly won't clog your petcocks or carbs. Top it off with clear gas after every ride.

I wouldn't line the tank until it started rusting. Which might never happen. Why risk the liner failing to address a non-existent problem?

Do we know what the Emgo tanks are made of? Is the interior of the tank plated with something rust resistant (zinc flash, etc)? Or is it plain steel? And how does that compare to what the original tanks were made of?

Stephen Hill

<sarcasm=on>
Yeah Davo, don't listen to your painter. Wait a couple years until the crappy Asian steel begins to flash rust (which it will) then you can have fun rinsing-out your freshly painted tank with acid and detergent and going through all this BS while worrying about ruining your $500 paint job.
<sarcasm=off>

Kidding aside, gasoline can weep out of the smallest pinholes in a weld that won't show-up with water and pressure. I've seen this with my alloy Atlas tank.
We pressure tested it to several PSI with soap + water and it was fine. Filled it with gas and it would weep after an hour through some microscopically small pinhole.
It will break your heart. Seriously.

As an aside, I have one of these Emgo tanks on my 850 which was repaired by Ross Thompson (before I bought it) and it looks like he uses POR-15 to seal his tanks.
It's a black textured coating that is still tough as nails after 3 years of midwest gasohol, so I'd feel safe with this stuff too.
Ross knows a thing or 2 about motorcycle gas tanks so I trust his decision completely.
http://www.execulink.com/~rosst/

I prefer the Caswell because it's clear and smooth as glass and just plain feels nice if you ever stick your finger inside your tank.

If you want to test a new tank for leaks, fill it with diesel.
We found in the automotive filed , that petrol tanks that were kept full, never gave problems. Its the air combined with a little water that causes the corrosion. Also a full tank doesn't develop much vapour pressure, so your fuel wont evaporate, and fill your garage. Prove it by adding 10l to a 20l plastic container at your petrol station then look at the shape of the container when you get home. It almost bulges like a ball. However if you fill it completely to the top, you can drive round with it all day in your car and it wont bulge.
Dereck
ps, I have an old steel 10l container at home which I use to fill my bikes but I purchase it in the 20l container. I keep the 20l container completely full until the 10l one is empty and my bike is low. I fill the bike and 10l from it. Then I have to leave the 20l's lid loose or it will swell up. Needless to say, this happens when I am riding a lot so the 20 is hardly ever part full.
Dereck
Bit off subject but related anyway.