Gas tank question 39 ford

There was a sealer in the old days that worked fine until the new gas hit it, then it shreds and tears loose. Make sure you don't get that obsolete sealer.
 
I may be wrong, but i canot see any reason to seal a tank. That sealer is what causes most of the trouble with the fuel tanks to start with. That tank has lasted 72 years without sealer, so why put it in now. I bought a new tank for my Ford pickup a year ago, and it came with sealer in the bottom of it. I thought that it would be ok because it would be set up for our new fuels. It sat full of fuel for 2 months and i needed to use it. I made it 3 miles. When i got through checking things out i took the fuel tank off and the sealer turned to goo in the tank, filters and fuel line. No more sealer for me again, of any kind. Marv
 
Marv, original tanks were tern plated, which was a type of galvanizing, a lead/tin rustproofing. Over the years, the tern coating would gradually go away, and the natural thing happened with the tank being steel, they rusted. This is why the sealers were introduced. Today rust is even more of a problem due to alcohol laced fuel posing an attraction to moisture, and the old sealers are incompatible, so new formulations of sealer have been developed.

Sorry, I haven't heard of any "New" tanks having sealer, and why would there be sealer only on the bottom? Niether of these sounds right to me. Not doubting what you said, but you may have been taken for a ride on that "new" tank.
 
Ive been reading up on sealers, Im looking for one that is impervious to alcohol naturally. I intend to seal it because I blasted it and its bare steel inside and I have a feeling that some areas of steel are kinda thin. I found some interesting prospects on the Aircraft spruce website. Im also thinking of using west epoxy inside. I still have more research to do. Here are some pictues after sandblasting the inside
 

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Marv, original tanks were tern plated, which was a type of galvanizing, a lead/tin rustproofing. Over the years, the tern coating would gradually go away, and the natural thing happened with the tank being steel, they rusted. This is why the sealers were introduced. Today rust is even more of a problem due to alcohol laced fuel posing an attraction to moisture, and the old sealers are incompatible, so new formulations of sealer have been developed.

Sorry, I haven't heard of any "New" tanks having sealer, and why would there be sealer only on the bottom? Niether of these sounds right to me. Not doubting what you said, but you may have been taken for a ride on that "new" tank.
The truck tank i was talking about was for a 89 pickup and i think it came from a supplier out of California that sold body shop supplies etc. I cant find the sales order to give the name. I know about the alchohol etc, and i do not know of any sealer that alchohol does not destroy. Yea i know there is different brands that say they work but have not found one that does. The make some for aircraft and they donot work. Marv
 
Seal it after you weld it. The sealer has vapors and if it gets burnt you will have a bigger problem than you had. I always thin the Redcote with about 25% acatone so it covers the inside better. It takes about 2 quarts so it runs around good inside covering all surfaces. Don't do it in the sun or it will form air bubbles drying to fast. Drain the excess back in the can and it can be used years latter. Turn the can upside down so the sealer seals the lid. Let the first coat dry on saw horses turn it every 4 or 5 minutes so you don't get ice sickles. As it drys the outside surface will become cool as the thinner evaporates. When it gets to room temperature it is pretty well set up. Wait 1/2 hour and give it a second coat. You can stick you finger in and feel it. I wait about 2 days before filling. G.M.
 
Well I started welding the tank bottom to the tank top and I ran into a problem with the bottom metal pulling away from the top metal as it was heated (too large a gap)

I will have to use cleco's to hold the pieces together and tack weld it every couple inches before I can finish weld it. Otherwise its going ok.

Well the cleco's didn't work. If you get to close to them welding the heat ruins the temper of the spring inside. I ended up using 1/8 inch sheet metal screws every 4-5 inches.

Gary
 
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Brasing is the way to go. Faster and less distortion. Got 2/3rds the way around it before I ran out of acetelyne. It will have to wait till monday now.
 
Gary, I think you're playing with dynamite there. Brazing is not joining the two halves together, you're just sticking them together with glue. You need to make the two halves into one whole by welding. We don't want to hear about a '39 Ford that went up in flames in Missouri... and your house... and you.

Tack weld in spots around the perimiter, then come back and spot in between. Keep that up until you have spots close enough to make a weld between a couple, and on and on.

Hell, if you can't git er done, we'll take up a collection for you. Don't braze it!
 
Gary, I think you're playing with dynamite there. Brazing is not joining the two halves together, you're just sticking them together with glue. You need to make the two halves into one whole by welding. We don't want to hear about a '39 Ford that went up in flames in Missouri... and your house... and you.

Tack weld in spots around the perimiter, then come back and spot in between. Keep that up until you have spots close enough to make a weld between a couple, and on and on.

Hell, if you can't git er done, we'll take up a collection for you. Don't braze it!

I appreciate the offer of a collection, but I think this will work. Of coarse I will monitor it closely, and if for some reason it doen;t work, I will admit it and let everyone know.

When I was a kid, my uncle owned a body shop and my father worked there. Ive seem a lot of brazing and so long as its a lap joint, not a butt joint, and the part is not in bending load, a properly braised joint will be there when the steel is rusted away. The only down side to braizing is once its braized it can;t be ever welded again.
I did tack weld it all the way around to make sure the thing couldn't move and I have a 1 inch lap joint. I then braised the rest. I intend to clean the welded/braized area by blasting (after tapeing off the openings) and coat the outside with west epoxy and the inside with some kind of sealer. (still not decided on what kind to use) I think I have about 4 hrs labor into it.
 
Well,

I finished up brazing the lap joint around the tank yesterday.

I found (after a little pratice) that propane and oxygen work fine for brazing. A heck of alot cheaper too.

I sandblasted the outside bottom to remove any scale and flux and left it in the shop all day with the heat on to come up to 65 degrees.

Tonight I coated the outside bottom and seams with West epoxy. Looks good so far. I will know for sure in the morning. Lots of trouble but very little cost. Probably 5 1/2 hrs total labor.

Gary
 
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