Very off-topic pet-seal question!

[mark_in_manchester]

Ethanol in unleaded petrol has finally dissolved enough of the old pet seal in the tank on my non-diesel Ural to cause it to seep, as well as periodically blocking carbs. I need to get the mess out, and re-seal it.

I hope to get most out by wrapping tank in loads of blankets and running in my cement mixer, packed in tight, with a big handful of chipboard screws inside.

Once worst is out mechanically, I understand solvents are available. Anyone tried them, or any of the 'new' pet seal products which are resistant to ethanol?

cheers
Mark

[tappy]

In my experience Petseal is utter rubbish when compared to POR15 which covers better, bridges holes better and sticks like the proverbial. Not sure about the ethanol resistance but I've never heard of anyone having problems. Frost Auto Restoration sell a motorcycle tank kit - includes etching primer etc. In my experience they underestimate the coverage & it'll do tanks up to 4.5 gallons.

[sbrumby]

Maybe try the method i used, put the tank on the outside of the mixer secured against the filling hole by straps tied to the mixing paddles, obviously padding the rim of the mixer.

[mark_in_manchester]

Good idea Sam - if I padded it, I could hold the top of the tank against the mixer rim using one ratchet strap running the length of the tunnel via the paddles. OK, I'm nearly enthused enough to start...!

[coachgeo]

Good idea Sam - if I padded it, I could hold the top of the tank against the mixer rim using one ratchet strap running the length of the tunnel via the paddles. OK, I'm nearly enthused enough to start...!

Take a pic please when you do this. Sure Im not the only person reading here that is not familure enough with what a mixer looks like..... where it's paddles sit etc. etc.

[albertaphil]

Thanks for breaking cover for me coach. Not that I have even googled it, but I'm still stuck wondering what pet seal is!

[Eddy Wane]

Pet seal - Petrol Tank Sealant. A specially formulated type of "paint" that seals the inside of a fuel tank against the corrosive effect of fuel and its additives and to prevent the formation of rust which could contaminate fuel and block jets and injectors etc.
There are surprisingly a wide range of products that are used as sealants it also helps (stops) weeping especially on fibreglass fuel tanks.

[albertaphil]

Huh. Well thanks for that Eddy. Learn something new every day!

[mark_in_manchester]

We use it to seal rust in, and to seal small holes and splits which otherwise would require 'proper' mechanical repair. I used it on my Ural-Daihatsu, where I found my welding of bases into new tanks was structurally adequate, but by no means diesel-tight. This sort of fix lasts well - or rather did, until ethanol started to get added to petrol which dissolved the old formulations and turned them into peeling sticky leaky gunk. Yes, I'll take pics when I get started with it.

cheers
Mark

[gilburton]

Petseal Ultra is supposed to be a new formula to combat modern fuels breaking the coating down.
The "mixer" Coach, is just a simple concrete or cement mixer. You must have seen them in the US??
By strapping the tank to the large hole and running a strap through the internal fixed paddles the tank can be cleaned out of old petseal or rust by filling with handful of nuts/bolts and letting it rotate for a few hrs.
The angle of the mixer can be changed to make sure the tank is fully cleaned out.

[pietenpol2002]

And for those of us who don't own a "mixer" it gets wrapped in blankets and stuffed in the clothes dryer on "no heat" setting. And I've even done it with my wife in the house.

[coachgeo]

....The "mixer" Coach, is just a simple concrete or cement mixer. You must have seen them in the US??...

Yes, know what a Cement Mixer is .... just never stood close to one..... seen it's paddles, etc so picturing how one would tie in place is completely baffeling.

[Diesel Dave]

Wait 'till the wife has gone shopping.

Take all the cushions off the couch.

Throw a handful of nuts and bolts in your tank.

Use the tumble dryer, line it with the cushions and put the tank in the middle.

Run it for as long as she's not about.

Disclaim any knowledge of why the dryer or cushions stinks of fuel afterwards.

Essentially the same rules as using the dishwasher for cleaning engine parts.

[Tetronator]

As explained...

https://www.youtube.com/watch?v=i7I1O0K7EF8

[mark_in_manchester]

OK...2 or 3 hours in the cement mixer did something, but still loads of old petseal inside. Following something of a hiatus, I'm going to try this very animated Scotsman's approach:

https://www.youtube.com/watch?v=5yQ8O69c-0Y

So tank innards are now soaking in caustic soda. Let's see if it will take old pet seal off...

[gilburton]

Just watch your eyes!!! Put some safety glasses/goggles on and have some water nearby to rinse off any splashes on yourself.
We used to do this years ago to decoke 2 stroke exhausts.

[mark_in_manchester]

Well folks, tank has been sitting with about 5 gallons of water in it and a full pot of caustic soda from the ironmongers. It sat like that for 3 or 4 days and some old sealer came away. I then added electrolysis - 4A current at about 3v from bench PSU. The tank is -ve, and +ve terminal is two strips of thin steel which run down either side of the tank tunnel, with nylon screwed to ends to insulate them as they rest on base of tank, and the other end carefully coming up through filler hole while not touching the sides. Been bubbling for a week - small sheets of sealer keep floating to the surface, and now and again I have had a scrape inside and it has been possible to pull larger pieces away (GOGGLES!). Tank top (old 650 Ural) is obstructed by a tool box, so getting to the back end is impossible with a scraper. Who knows how much longer I have to run for - over a week so far.

[OilyPhil]

Hi Mark, I used a product called petseal remover, I got it off e bay, it turned the petseal into small grains like sand which were easily washed out. Following that I did the electrolytic process to get rid of rust, then recoated with POR21 from frost automotive.

Phil

[mark_in_manchester]

thanks - I've looked that up. The only thing is, I can't remember the product I used to seal it originally, years back - all I know is, it was 2 pack, and it's red in colour! I wonder if the petseal remover would work. Caustic soda has cleaned the tank sides and top pretty well, and I think it would respond to another trip in the cement mixer. But the tank base has a layer 1-2mm thick which is still hard and resistant. It is soaking in some xylene-based thinners at the moment which don't seem to be doing much - I have some other cellulose thinners on the way which I could try, and I may borrow some acetone from work. I've even started to wonder about using the POR product over the top of this tough layer - if it would bond to it, and seal it from ethanol in petrol. Hmmm.

[mark_in_manchester]

OK - Xylene is out, and didn't do much. Tetrosyl cellulose thinners are in, and made short work of a test piece in a test tube - now seem to be having some effect on the thick layer of old sealant in the base of the tank, but it's very, very slow.

[mark_in_manchester]

OK - cellulose thinners are finally having an impression - thick layer is swelling a little, coming sway from the tank base here and there, and with a scriber under it (only possible near the filler neck) it breaks off in big sheets. So I'm going to leave this in for another week before investing in the nuclear option (MEK - recommended to me on Russian bike forum, and available from ebay) if it's still not there yet. I've collected some more sharp heavy scrap from work, for the next run in the cement mixer!