Treating Corrosion Inside Frame Tubes

[RoamingStar]

Hello BCF, I couldn't find an 'Introduce Yourself' thread (I may be thick and have missed it) so before I ask my question:
I've been riding on and off over the years, scoots, 2smokes, little Japs, a Chinese monstrosity and my favourite a Ducati ST4. I'm now the owner of a 1959 BSA C15 Star which is currently completely stripped for a "quick refresh" as I had the audacity to ride it in the winter and it started to dissolve a touch.
As it's apart I've noticed there is corrosion inside the frame tube. I'm painting the outside as part of the refresh but I'm not sure what to do about the inside. It doesn't look bad (although I can only see so far down past the headstock) so it may not need attention but it seems daft not to sort it as it's already in bits.
I was thinking of using a POR15 tank sealer kit as I did for the fuel tank. It has a bottle of wash solution, a bottle of etch and a bottle of liquid tank liner. It'd be a bit of an uncertainty as to whether all parts of the interior had been reached but turning it every which way should do the job. I'd also have to come up with a way to plug the headstock so none of the liner got on the surfaces the headstock bearings sit on. Would this be overkill/a bad idea for any reason? Would simply dumping a bottle of rust converter in there suffice? Should I leave well enough alone and not worry as it's unlikely to be rot and merely surface corrosion? The frame is nice and solid (and straight) and I'm only painting it as the existing paint has worn through in places to the metal looking unsightly. I intend on riding the bike quite regularly, it's not going to be a concours/garage queen more of a decent looking but definitely used mount. I'm not painting the tinware for instance as it's overall pretty good and any imperfections that are present mean I'm not going to be too precious if it gets marked whilst in use.
Any advice or opinion offered is appreciated.

[to v or not to v]

welcome to the forum
you should find some sound advice here, and maybe a bit of light abuse, some people like to wind up new posters.
dont take it too seriously, and good luck with the bike.
____________________
current bike Yamaha Thunderace.
Moto Guzzi V7.

[RoamingStar]

[Fat Angry Scotsman]

[RoamingStar]

[RoamingStar]

I still sit like that sometimes, even after all these years...[/img]

[to v or not to v]

[Fat Angry Scotsman]

[Easy-X]

Might we get round to answering the OP's query?

I think what you're after is cavity wax, e.g. Dinitrol.
____________________
Royal Enfield Continental GT 535, Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[stinkwheel]

It's probably decent quality chromoloy steel with brazed lugs on a C15 frame and it'll also be massively thick compared to a modern bike so I doubt a bit of rust on the inside will be too much of an issue.

POR15 would be one solution but as you say, i think it'll be overkill. It'll also be very difficult/impossible to get the inside properly dry after flushing and the POR15 coating is almost impossible to get off again if (when) some of it finds little holes and gaps to creep out of. I saw one account of a guy who painted his trailer chassis with it then needed to remove some to weld on it and not even one of those nippy grinder mounted wire brushes was marking the stuff.

If it was me I'd either do nothing or squirt a liberal amount of ACF50 in through any orifices I could find then forget about it.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[RoamingStar]

[RoamingStar]

[jeremyr62]

You could slowly pump in old (or new if you prefer) engine oil or ACF50 from a low water drain point, plugging leaks as they appear with plasticene or blutac. When you think you are the top of the frame, just let it all drain out. It will drip out for a long time though. I did this with a VF500 frame and it was easy enough to do.

[Nobby the Bastard]

Surely it would be easier and cheaper in the long run to find someone who can dip the whole thing in phosphoric acid?
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[WD Forte]

On my old CXs which like many bikes rotted from the inside out
I used to weld them up and paint them then flood the frame
and swinging arms with old engine oil sometimes thinned with a bit of white spirit.
Then I'd turn the frame upside down and round and about to get it into every nook and cranny then let ( most of it) drain off.

The swinging arm which I repaired and did this to in 2005
was still sound when I sold the bike 2 years ago.
I also introduced a few 3mm holes in strategic tricky places to enable me to get a nozzle in to squish ACF50 and or WD 40 the areas around the engine hangers from time to time.

Never had any tin worm problems after that and my current scooty
frame was treated the same when I fixed it up
Yes you heard me, scooty
____________________
bikers smell of wee

[WD Forte]

[stinkwheel]

Anyway, a scooter is almost certainly faster and more reliable than a BSA starfire.

I had a comedy moment, I was riding my 350 bullet with a trailer and my mate was riding his BSA B40 on the M56 when we were both passed by a 1964 Honda C90.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[RoamingStar]

[RoamingStar]

[RoamingStar]

[RoamingStar]

[RoamingStar]

[WD Forte]

I had a 59 Tiger cub and IIRC this and the C15 had similar dome shaped
distributors.
Parts sharing perhaps?
cba to look up when Triumph and BSA amalgamated
____________________
bikers smell of wee

[Bhud]

Rust converter, and don't ride it.

[stinkwheel]

Remeber, they didn't make the electrics, Lucas did.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.