Just when I thought I was done the rear seam that seems to have been previously fiddled with is seeping a drop or two an hour with a gallon in tank. So if full would prob increase. 

can anyone recommend something that I could slosh around inside tank to seal this since I don’t want to ruin clear coat or blow up house trying to solder. 

thanks for your help!

martin 

 

I had my DT1 tank all sealed up nice but didn’t see there was a sharp piece of weld sticking up from the frame that added another hole to my just finished tank.  Right in the same spot your screwdriver is pointing.  I ended up using the 2 part fuel tank repair epoxy they sell at autozone, I think it was permatex brand and it seems to be working fine, no more leak and I did it a couple months ago. It’s the stuff that’s a roll of 2 kinds of putty you cut a piece off and kneed together then just stick it on the leak and let it cure for a day or two. 

I’m using “Original Kreem” tank liner. There’s a previous thread about tank liners and I was at the point of not using one but I’m going through such a faff with de-rusting and prepping I couldn’t bare to see rust reappear after new paint.
Another plus note is the Kreem brand liner is an air drying product and if in the future you want to weld or recondition your tank again, this stuff devolves with acetone. 

I've seen several failed liners...  what a mess.  Hope your experience with lining the tank doesn't end badly in a year or two.  Careful prep exactly by the instructions seems to be the key.

Good data

The leak is in the seam in specific area at rear of tank. Could I dry it out and then find a way to get a load of epoxy to inside side of seam and down into “v” by standing on end?

if I could seal from inside in this area and have it adhere then I think I would be in good shape. 

good or bad idea?

POR15 do an external seal that at least one forum member has used successfully.

At one stage I had three leaking tanks and I bought some POR15 to fix those. I then decided to give two of them to a local engineer to try and braze them - one was successful, but the other wasn't (which is a shame, as it's a really hard to find RD125 tank), so I'll probably try the POR15 on that. I haven't looked at the third tank yet.   

I've welded lots over the years but in your case --'paint'--so solder using a descent size iron to hold the heat is good. Using a good flux to get it to 'take'. Trouble 'is' getting it clean enough to solder. Can you trap some epoxy glue stuff in a small wrap around plate to cover the area considering it'd be difficult to get epoxy to stay there until it sets. Annoying when that happens.

thanks RT325 and Gr8... 
I think I will take the lightest hand and buff down the seam area with a small wire brush in a drill, then create some type of containment and orientation t to keep some fast drying epoxy in place on seam.  Hope to be able to report back success, thanks

I have had a recurring slow leak or weep in both bottom corners of my 68 Dt1 tank for 5 years now. Originally was unaware of it until I painted, pinstriped and cleared tank. Noticed the leak, ruined the paint. Stripped finish paint, cleaned area, soldered and repainted the tank. Repeated this process after leak recurred once more. The leak came back a third time and I stripped back down to primer, as she sits today. I took a hiatus on the bike but recently removed the old liner (kreem) with great results and took another wack with silver solder. Holding up well for now but I am riding the bike as much as I can for a while to see how it holds up. Adding a new liner to a tank that could otherwise be cleaned to solid bare metal will impede any future repairs, ie welding, soldering or brazing. The liner, if it fails as it did on mine, will need to be stripped. As will any finish paint. Would not trust any liner or epoxy to stop these leaks on the bottom seam, it will just stretch and tear, especially after the tank is installed and you go for a ride! 

Thx brigsy, silver solder prob excellent way to go assuming you were able to get it to flow into very small dirty crack

I went with fast cure epoxy after wire wheeling area clean and abrading with 80 grit paper.

Filled all the way up today so we shall see! My leak was like a 4”x4” overnight wet spot so I am hopeful. If this fails then it’s onto plan b