What is the consensus on these gas tank repair kits where you clean, etch, and pour in a liner compound?

I have a small leak near the tank drain plug. It looks like it has been brazed before (or it’s the factory brazing when the drain valve was installed). I have not taken the tank out yet, or opened the sending unit hole, so I do not know how bad it is inside. The outside looks in very good condition with the tar still intact. I think it sat around empty for a long time since the tar only came off at the very bottom as a result of me putting fuel in the tank.

I was also thinking of brazing it myself after washing it out.
What should be used to clean off the buildup on the inside of the tank? I was thinking of cleaning the inside of the tank, filling it with water and then brazing the damaged area. Any suggestions?

Also, after dealing with the leak and interior, I also heard of using some epoxy resin to cover the outside of the tank. Wonder about epoxy resin vs. using rubberized under coating from spray can (chip guard).

In a previous lifetime I was removing underground storage tanks from gas stations all over southern California. Before we could pull the tank it had to be cleaned and inspected as non-hazardous. The problem was that the tanks usually only had a 3-inch connection at each end making it difficult to get a high pressure sprayer inserted let along the hose from a vacuum truck.

Our solution was to use a jackhammer and a specially ground bit that would let us cut an opening like an old fashioned can opener. The problem was, of course, jack hammering away on the tank was a hazardous endeavor. The solution to that was that I showed up an hour or two before the cut with a couple hundred pounds of pelletized dry ice which I dumped into the tank using a cardboard funnel. I had a meter that measured the presence of volatile organic compounds and when the reading when to zero we started hammering.

It seems that the same could be done on a gas tank of a car. Clean the tank the best you can and then drop in a bit of dry ice. When the fog starts coming out the fill tube it should be OK to hit it with your die grinder.

Vince in Montana

I once used equal amounts of muriatic acid, paint remover and water in a heavily varnish and rusted gas tank that sat for over a decade. Cleaned the tank right out in 20 minute and it shined like brand new!!! I recommend doing this outside and standing back a bit though. Up wind I might add...

Probably best to have a shop do it but I guess I like to do everything the hard way. I had a similar small pinhole. I took the tank out, peeked inside and saw a horrifying mixture of rust/sediment/gum in there. It was bad enough that I decided to cut out a section of the bottom for a better look. Obviously you need to clean the tank thoroughly before working on it.

I aired it out by blowing compressed air through it while it sat in the sun on my driveway on a 95F day for several hours till there was essentially no smell of gasoline. I washed it with detergent and water and made the first cut while purging generously with air (discharge side of a shop vac through the inlet fuel opening and out the fuel sender hole...don't use the suction side because the shop vac motor can ignite fumes). I'm still here but don't recommend anybody do this if they aren't absolutely positively sure the tank is free of flammable fumes.

What I found was that there were two large areas of the bottom that were pitted badly. I cut those sections out, which left me holes large enough to reach in there and sandblast the entire tank from the inside. the rest of the metal was in great shape. I welded in new metal patches, and used por15 gas tank coating to put a corrosion resistant seal on the inside. It was pretty easy to use...just pour in, seal up the tank, roll it around a while, and pour out the excess. I found the quart can is about twice what you need for these little tanks. There are no baffles in there (at least not in mine) so complete coverage is easily done. Total cost was the por 15 + etch solution which totaled I think around $60.

It looks great but haven't put it to the test yet since the vehicle is months if not years away from being on the road again.

Dean
'61 455 & '69 1800

Gas Tank is out of the car, and level sender removed.

Exterior of tank is in very good condition. Interior bright orange covered everywhere I can see including the filler pipe. Vehicle has been sitting for long time, probably no gasoline in the tank at all. Do not know thank history, just purchased vehicle. I poured a couple of gallons in the tank with new inline fuel filter and engine runs fine. The gasoline softened up some of the rust. I was able to shake out some rust paste.

Option 1
New gas tank is listed around $310 plus shipping, taxes etc, probable be near $400 out of pocket price (OPP)

Option 2
Repair shop will restore it for $250 - $300 (283-340 OPP). Restoration means repair of all holes and pouring a liner inside it. At this point I would probable epoxy resin cote the outside.

Option 3
Do it your self liner kits go from $50 -$ 75, locally the POR-15 gas tank repair kit is available for $100. I have seen some videos where some people are using aquarium gravel in their tanks with water or some rust dissolving compound to clean out the inside before etching metal.

Option 4
I’m also thinking of possible making a new tank out of Aluminum. I have a 230V Lincoln welder which can be outfitted with a feed gun attachment to handle aluminum. But I would have to purchase the gun, a bottle of 100% argon and aluminum. The cost would be around the same as purchasing a new tank, but I would be set up for also being able to weld aluminum. If I was to go this way, it would be a long term project and I would like to have use of the vehicle now.

Option 5
May last option and an interim solution would be to do the minimal amount for it to hold gasoline. Thanks to all of you who fed back.
So, I could just clean out the tank from the rust, find the holes, if not too many and JB Weld them. Spray some rubberized undercoat on the tank and put it back in its place until I decide on a proper long term solution.

I still have some body holes to plug up in the vehicle before attempting to get the safety certificate. Just rebuilt the brakes and electrics seem to be working with some minor repairs needed. Just want to get this thing on the road and drive it a bit this summer. Oh yah, and find out some more potential hidden failures which require attention. At some point my objective is to perform a complete disassembly and restoration.

Hello,
Who's selling new 544 fuel tanks these days?
Thanks,
Mike

available from CVI

http://www.cvi-automotive.se/en/articles/2.5255.40670/fuel-tank-pv544-b18-late-b16-from-ch-264990

If you have a hole from corrosion you will have more. Some tanks like mine had corrosion on the top from sitting and the condensation inside the tank rusted pin holes from the inside. I took my tank to a Gas Tank RENU dealer. They repaired the tank with patches also pressure test and guaranty. $260 and the tank is like new inside and out. Radiator and gas tank repair shops are not easy to find like years ago, most repair shops today replace new parts and don't repair anything anymore.

I had mine repaired recently. It was boiled out 3 times; and there was no corrosion or rust left. They also soldered all the holes, and added a new drain cock in the corner. Total was $220. I then painted the outside with black POR-15 and it looks new.

You can use methyl ethyl ketone as a great solvent to clean the tank out, but I would find a good radiator specialist.
--
1959 Volvo Amazon 121, 1998 Volvo V70R AWD

J-B Weld is not gasoline tolerant. They might make some J-B Weld for gasoline, but the regular brand does not work well with gasoline.

J-B Weld is not gasoline tolerant.

Really? I'll have to mention that to my PV's gas tank. I repaired it with J-B Weld ten years ago. Not to mention the fuel pick up tube connection on the tank of my 142E which has been sporting a large, unsightly but effective, blob of the stuff since 2008. ;-)

I also repaired a mechanically inflicted gash, several inches long, in the bottom of the oil pan on my Scout II snowplow with fiberglass cloth saturated with J-B Weld. It was still holding nicely after eight years, when the stalwart little truck was hauled off to its unjust reward in the junkyard.

How do you saturate fiberglass cloth with J-B Weld? You put it in a plastic sandwich bag with a substantial blob of the stuff and knead it thoroughly.

What you do want to keep away from your fuel tank are the silicone-based adhesives.

BTW, I fabricated a fuel tank for my boat out of plywood, fiberglass and epoxy resin. J-B Weld is basically epoxy resin, hardener, powdered metal and marketing.

http://jbweld.net/products/jbweld.php

All conventional PYA caveats apply to this post.

--
‘62 PV544 (B20, M41), '71 142E (Ex-automatic, now carbed), '93 240 Classic Wagon.

Before you go the brazing route, drain the tank completely and leave the drain hole and the filler pipe open to give it a chance to dry out thoroughly; clean around the leak with a solvent that will remove all residue of undercoating and evaporated fuel; wire brush and clean again with, for example, acetone; J-B Weld liberally and let cure overnight.

If that doesn't do the trick, you can always resort to brazing or soldering - no great feat, especially if you remove the tank from the car, have the equipment for it, and make damned sure the tank is clean, dry and well-aired. If, however, you aren't entirely confident of your skills in this sort of thing, by all means, take the tank to a radiator shop.

--
‘62 PV544 (B20, M41), '71 142E (Ex-automatic, now carbed), '93 240 Classic Wagon.

I would drain it and take it to an old-time radiator shop that is set up to do it right and safely.
--
George Downs Bartlesville, Oklahoma

I would be interested in how you plan to clean the inside.

I vote for having a pro clean and repair it.
--
'96 855R,'64 PV544 driver, '67 P1800 basket case, '95 855, '95 854, the first three are mine, heh, heh, 485,000 miles put on 9 bricks

I've done a number of tanks with the POR-15 kit. I'd do that if it were me. The oldest reworked one was done ten years ago and it's still going strong. Not a sign of aging in that tank.

The rustiest tanks I have played with (70+ year old tractor) I poured in a couple of pounds of screws and shook the tank and screws for a few minutes. It tooks some time to clean out screws and rust but it was better.

Follow the POR-15 directions and take your time. I figure it's ten day process to do all the steps and have it dry between them.

For tanks with clear holes in them, use some epoxy puddy to plug them up, then clean and etch and line the tank. If you notice small holes weaping during the etching step, simply put masking tape over them. This will keep enough of the liner there to seal the hole. Remove the tape once the lining is set (two or three days).

Like I say, I've had great luck with the POR-15 kit in several of my own cars and a tractor.

This approach worked for me as well.....at least it has for six or so years, now.

The step where you shake it up with hardware and gravel sloshing around inside and then poor out the results is, somehow, satisfying.

Keith W.
'58 444 / B20
'89 740T Wagon