question Sealant for petrol leak

[fv1609]

We've discussed these sealant fluids that are swished around the tank, particularly useful where there is widespread corrosion. But what I am after is some reliable sealant to block a tiny seepage from a definable crack, that could be applied externally to the defect.

 

I removed the tank some months ago & had it steam cleaned. The base of the tank was a replacement & braised on. After the cleaning the base looked in very good condition.

 

The seepage I am getting is visible from the crack between the arrows where the boss has been braised on. It is very slow it takes about 10 mins before it is damp to the finger, so I am hoping that there is some sealant that would set quickly enough.

 

It is a bit of a fiddle getting the tank out of the Shorland & I am scared of brazing with risk of residual vapours. Even if I used the gooey fulid & swished it around it would land in the boss & drain plug making drainage impossible.

 

Anyone got any recommendations please?

 

[Marmite!!]

http://www.shopwiki.co.uk/_Plastic+Padding+Leak+Fix

 

Good stuff...

[croc]

This stuff is pretty good Clive.

http://www.kalimex.co.uk/section.html?secpath=01.06.&pgid=6

[fv1609]

Does it have to be 100% dry? Given my very slow rate of leakage, once it is on I was thinking of using a hot air gun to speed it up.

[Marmite!!]

Does it have to be 100% dry? Given my very slow rate of leakage, once it is on I was thinking of using a hot air gun to speed it up.

 

It will take if the tank is damp... I have a new tube here that I can post to you, just opened it to seal the Foxes new pick up pipe in place... it will only go off in my toolbox so yours if you want it...

[croc]

The quiksteel stuff will set underwater. I have used it to repair holes in fuel tanks that are dripping by using a small blob to plug the hole then clean/degrease and make a bigger patch over the top. I recomended it to Adam a couple of weeks ago for fixing a leaking diff on his Pig, worked no bother.

[fv1609]

It will take if the tank is damp... I have a new tube here that I can post to you, just opened it to seal the Foxes new pick up pipe in place... it will only go off in my toolbox so yours if you want it...

 

 

Yes please that's very kind of you Lee. Have you still got my address or shall I PM it?

 

Just booked in the Shorland to the Eastnor LR Show for 6/7 June which is 95 miles, so don't want to worry about the leak getting worse. Was going to a local event but no reply to my entry & to two emails so thought I'd try this one. Never been to a LR show, hope there isn't too much in the way of wide tyres & Camel Trophy nonsense!

[Marmite!!]

Yes please that's very kind of you Lee. Have you still got my address or shall I PM it?

 

 

 

PM me your address again & I'll pop it in the post in the morning..

[poppypiesdad]

what about the frost stuff and line the tank itself

 

www.frost.co.uk

 

just got all the stuff but not did it yet

 

http://www.frost.co.uk/how_do_i_explained.asp?hdID=32'>http://www.frost.co.uk/how_do_i_explained.asp?hdID=32'>http://www.frost.co.uk/how_do_i_explained.asp?hdID=32

 

or

 

http://www.frost.co.uk/how_do_i_explained.asp?hdID=3

 

Jamie

[Tony B]

Petropatch works very well. It cosists of a cloth that is put over the hole then a grey goo is applied. I can state it lasts at least 15 years. I've got a tank sealed with it to prove it.

[Marmite!!]

what about the frost stuff and line the tank itself

 

www.frost.co.uk

 

just got all the stuff but not did it yet

 

http://www.frost.co.uk/how_do_i_explained.asp?hdID=32'>http://www.frost.co.uk/how_do_i_explained.asp?hdID=32'>http://www.frost.co.uk/how_do_i_explained.asp?hdID=32

 

or

 

http://www.frost.co.uk/how_do_i_explained.asp?hdID=3

 

Jamie

 

As Clive said...

 

We've discussed these sealant fluids that are swished around the tank, particularly useful where there is widespread corrosion. But what I am after is some reliable sealant to block a tiny seepage from a definable crack, that could be applied externally to the defect.

 

 

[Marmite!!]

In the post Clive...

[Guest catweazle (Banned Member)]

Cor theres a lot of bodgers on here :-D

[Richard Farrant]

Cor theres a lot of bodgers on here :-D

 

Yeh...........they'll be recommending Belzona next :-D

[Guest catweazle (Banned Member)]

Yeh...........they'll be recommending Belzona next :-D

I did think about it but the smallest tin would cost more than doing it properly :-D

[Richard Farrant]

I did think about it but the smallest tin would cost more than doing it properly :-D

 

 

Good point.............long time since I bought any.

[fv1609]

Cor theres a lot of bodgers on here :-D

 

I'm not rising to that!

 

This section is after all entitled "I may be stupid"

[Lardrover]

I removed the tank some months ago & had it steam cleaned. The base of the tank was a replacement & braised on. After the cleaning the base looked in very good condition.

 

 

Hi Clive

 

Have you got a spare tank that can go in it's place while you wait? How does it leak with only half a tank or less in. Not ideal but something to think about when not in use, condensation might be a worse long term issue though with empty tanks.

 

I've never had any joy with fixing such a leak by applying anything to the outside. Then again, I've not had a leak as minor as the one you describe.

 

I wonder if there is a product that seeks into the crack, a bit like the penetrating dyes for crack testing? One that will draw in via capillary action but possibly sets if it is a two part mix?

 

I've heard good things about the liquid sealant to slosh around the inside, can you not put a temp bung in place of the drain and then drill and tap with a thread cleaner so the drain plug threads into it?

 

It looks like there might be a better chance of having something seek it out from the inside, rather that try to get a good grease free key to the surfaces on the outside. I'd guess that the inside of the tank is clean around the are of the crack, perhaps apply several thin layers to build up?

 

Can you not fill the tank with water or aspirate with a CO2 bottle and try to sweat some solder in or chemically clean it and have another go at brazing?

 

Been Googling for crack penetrating and cleaning/adhesive stuff, would have thought someone would have had it by now.

[Guest catweazle (Banned Member)]

Captain Tollys creeping crack cure,used for sealing sea plane floats,used it for keeping water out of wood it dont arf creep.comes out miles away from where you put it in,dont know if its petrol resistant though.

[Lardrover]

After a long run home from Beltring, I need some of that creeping crack cure.

[rambo1969]

I can reccomend quicksteel, good stuff.

Cracked my front diff cover at W+P one year, whacked a load of this on and, bingo! job done.

Every bodger should have a tube in thier motor!

[fv1609]

Postman's not turned up with Lee's stuff & the more I think about it I want to try brazing it up. The worry is if the crack starts to spread as I have a round trip of 190 miles next weekend.

 

When I worked on the tank previously a friend steam cleaned it. But the logistics of getting that done is not probably practical. So I was thinking of pressure washing it with detergent & drying it off in the sun. My concern is for how long should I flush it before it might seem clear of petrol residue or vapour?

 

The main worry is that bit of petrol that had seeped through the crack in the brazing around the boss. One hears of terrible stories of exploding tanks from vapour residues. How can I be certain of cleaning the crack (no funny comments CW please). I don't now whether water could be arranged to drip or seep through, given that petrol seems to seep through waterproof seals!

[Richard Farrant]

I want to try brazing it up.

 

 

Clive,

 

Think very carefully before putting a flame to it. When we had to repair tanks in the workshops, they were hot washed or steam cleaned for sometime, then left for a period and a special meter used to "sniff" inside. The boss may have been soldered originally, so brazing may not be a good idea. If it is cleaned well around the crack, solder is best solution.

 

I actually use a radiator repair man for my tanks, they often do not advertise, but are well known in the local motor trade. Worth getting someone like that to do it.

[fv1609]

Richard

 

The base was a replacement as the original was rusted up. I was thinking of detergent washing it repeatedly. Then filling it up with water, surely that would displace any petrol & vapour? Then let it seep through the leak. Then put it out to dry & in a day or so work on it.

 

Though just wondering about soldering the crack. I have a heavy duty electric soldering iron that has a high thermal capacity as it takes about 15 min to heat up that way there is no flame. But it may not be sufficient. When I did the radiator, I had to use a flame on the surface to get a good flow, but there was water in the tank. But would flame soldering be less of a risk that full blown brazing?

[Marmite!!]

Should be with you by now Clive:confused:

[fv1609]

Lee, yes thank you it is here now, our deliveries are always a bit delayed. between 2-3pm weekdays & anyone's guess on Sat. I've now got the tank out & can see that there is some rust between the boss & the base of the tank. This has caused expansion & the outer soldering has cracked slightly.

 

Thinking about this, it can't be brazed as the boss is brass & would have melted, I assume it is silver solder or the like. I don't have anything like that so tomorrow I will attempt tin/lead soldering. I will clean the rusting crevice as best I can then form an internal ring of your sealant.

 

Once I have done my soldering, I will apply an external ring of sealant as a second defence. This of course far more likely to be successful, not just because it will be absolutely dry but I can work on it from above with no access problems.

 

The tank is now basking in the sun, but I'll leave it until tomorrow. Couple of good things come out of it. Firstly discovered the earth lead for the tank sender was loose & explains its intermitencey. Secondly one of the tank clamps was loose & I think the tank was jolted when I hit a rut & cracked the solder. If it hadn't leaked now then the expanding rust between the boss & the tank floor would have caused trouble at a later stage.