tinning steel

I am making a fuel tank for a reproduction Briggs and Stratton Motor wheel. I intend to use 2 1 lb Coleman propane bottles, with the bottoms cut off, tig welded together with a steel filler neck also tig welded in. My problem is keeping the inside of the tank from rusting and I came up with an idea - don't know how feezible it is. I am thinking of putting some Oakley 95 tinning flux in the tank after sandblasting it, and before finishing the weld then heating the welded tank to about 700F and rotating it while maintaining heat to totally flow the tinning flux over the entire surface. After cutting out the opening in the filler neck I would tin the inside ofthe filler then flush out any remaining flux - leaving the entire interior of the tank tinned and protected from rust - basically like a terne coating.

1.7 oz of tinning paste is $12.99 mini CanaBucks Can't think of a simpler lower cost source for a half gallon cylindrical duel tank - although this isn't exactly a SIMPLE one. I made a "prototype" brazing the tanks together and attempting first to braze, then to solder a red brass /copper fitting in for a filler. Not a neet job and not a liquid tight seel between the tank and filler - and a LOT of rust in the tank 3 months later.

What am I missing???? any obvious "gottchas"? ( I WILL braze "bosses" on the outside of the tank to drill and tap for the fuel fittings, and braze or tig on the mounting brackets before doing the tinning so no heating will be required after the tinning process )- then just a good cleanup and paint with gasoline-proof paint. I learned years ago NOT to use spray Tremclad on fuel tanks - - - -

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Argon or CO2 in the tank might minimize oxidation of the hot areas before they are covered.

A small stainless steel gas tank:

Why not use aluminum ? easier to form and since you have TIG capabilities ... I found that discarded late model GM truck aluminum drive lines are just the right diameter for quite a few small projects , I'm using a section to build a ball mill for making black powder for pyrotechnic projects .

Aluminum is an option but the "domed" ends of the tank come ready made on the propane tanks and I would need to come up with the proper aluminum filler neck - not impossible - but I'd need to source a 1 1/2 inch aluminum pipe nipple and I've got the steel one all made already - along with the brass cap and the mounting brackets for the 3

7/8 inch diameter tank along with the steel weld-on studs to mount it to the brackets. In other words steel will be a WHOLE LOT simpler.

My experience with POR in the past was it did NOT like ethanol fuel. Apparently it has been reformulated for stage II fuels?? I'd only need about an ounce - - - so it's an option - but I like the idea of the "tinned" tank - - -

Will an old school motor cycle tank Kreem kit do the trick? I never used one, but...

Like this

No you got me wondering if I saved the drive line off the 2500 I replaced or not...

Oh, I missed the ethanol on my first quick read. According the the PNW Riders, "It does not do well with ethanol (although they claimed they changed the formula)."

The thing is , you're pretty sure you did , just in case . You just can't for the life of you remember where you put it . I've been there ... way too often lately . They say that your memory is the second thing to go . I'll be damned if I can recall the first ...

Sounds complicated. Most ferrous metal fluxes for soft solder are acid, and can easily etch crevices that will trap moisture and rust. After it's all together there's not a lot of careful inspection of the solder coating possible. Why not sandblast, flux and tin the halves. then clean well and... use the same soft solder on a lapped seam to complete the closure, without flux (because the pre tinned surfaces will wick in fresh solder nicely).

The tank isn't for high-vapor-pressure butane or propane, I trust?

I don't know why this didn't go through yesterday.

Never used POR15 inside a gas tank but it never chipped off of my rear end. Biggest problem for you is that the smallest single can they sell is a pint for about $40. They have 4 oz cans but only as a sixpack for the same price as a quart, about $70ish. I've got about 3 unopened little cans left that I'll "never" use but I shudder to think what it would cost to ship it to you in Canada. They're 15 years old but still slosh when I shake them. If they did reformulate these are definitely the old stuff. If you want to go this way, maybe someone on ebay sells the little cans as singles?

Regards, Carl

Amazon lists half pints of the Fuel Tank Sealer for $19.30, with free shipping if your order reaches $35.