BSA Owners' Club Forum

The BSA Workshop => Twins => Topic started by: A10 JWO on 16 January, 2020, 17:52:15

Title: Petrol Tank Sealant
Post by: A10 JWO on 16 January, 2020, 17:52:15
Had a dent pulled out and some small holes repaired by the welder. I intend to seal the inside with one of the many products. Question, shall I seal it before it goes in the paint shop. I am aware that the painter will put the tank in some sort of oven to harden the paint, so I don't want to spoil the internal sealer, any views please.
Title: Re: Petrol Tank Sealant
Post by: GLENN on 16 January, 2020, 20:25:03
If he's painting with 2K paint then I don't think the temperature would be sufficient to do the sealer any harm.  If powdercoating then definitly too hot for sealer.  All the best, Glenn
Title: Re: Petrol Tank Sealant
Post by: chaz on 17 January, 2020, 00:28:36
Ahh, but a word of warning...I had a cheap , friend of a friend, Phoenix airbrushed on the tank of my a10 bobber. Tank was ok paint reasonable and the phoenix was feint not to stand our as the bike was quickly rescued from a barn fire.
Anyway, I decided to petseal the inside. I thought I had kept it moving about inside, but evidently not. The base coat cracked like crazy paving in one spot. Now the phoenix is ok the rest not.
If you want to seal the inside its 50 50 that one or the other may be affected. This winter I've pulled the tank off, and the brass fuel tap parts are green and rotten from the ethanol, likewise I suspect the original petseal may not be ethanol proof. .btw, the triumph chop has a new tank and carbs as the ethanol has destroyed the fittings and pipes in there as well. So make sure you get the new ethanol proof (hopefully) tank liner.
Title: Re: Petrol Tank Sealant
Post by: hoogerbooger on 17 January, 2020, 16:21:34
Can't answer your actual question, but I used the POR 15 sealing kit ( degreaser, Phosphoric acid, sealer) and didn't have a problem with it escaping. I wrapped the tank in cling film and used a correct threaded plug in the petrol tap hole and put a thin plastic bag under the petrol cap ( to stop it escaping via the breather) and could shake it as much as I liked with out liquid  escaping.

( however as I  was told that some sealers are transparent and it's difficult to tell if there is or isn't old sealer I preceded this with paint stripper...with the fumes ( it was a very hot day)and a little liquid escaping and damaging my old paintwork .... grhhh!............but it would be MUCH more annoying with new paintwork)

If you can't get a definitive on whether the heat will damage the sealer I would suggest, before painting, you practice with your chosen apparatus for making the tank liquid tight to check you have a reliable method. If you have a reliable method, you could get it painted first, seal later.

( ....for draining I put it on planks across a galvanised wheel barrow, then removed the plug & filler cap. This seemed to work well for me without any finding its way back up under the cling film)

( ps shaking was needed for the de-rusting with nails n stuff in. But the POR15 sealant just needs to be rolled around the tank, not shaken)

( also to note that petrol fumes now are lifting the paint I put pack around inner side of the petrol cap. I thought this was duff clear coat, but a colleague says he's had the same and it is sensible to use the sealant to coat the whole inside of the filler ( i.e everything under the cap)

good luck.

Title: Re: Petrol Tank Sealant
Post by: A10 JWO on 17 January, 2020, 16:44:04
Thanks for replies. I will seal it before it is painted just in case. I spoke to 2 paint shop staff today in person and they both agreed that sealing the tank first is the best option.