Rust inside steel frame

Just managed to remove a slightly stuck seat post and this is what I was faced with….

What would you recommend?

Spraying the inside with ACF-50, checking there’s a drain hole in the bottom bracket and doing the same from the headset -see if you can get some to run into all the tubes.

Looks like good stuff thanks. Would you bother trying to remove the rust I can reach. Thinking bit of wet n dry on a long pokey thing, or will spraying that stuff in just sort it?

I removed all the rust from a Singular Rooster once by soaking it in citric acid for a while. You can buy it in powder form and it’s cheap. The inside looked new afterwards.

First thing I do with a steel frame is stick a hole in the BB shell.

I’d be checking the BB bearings

No BB drainage hole at the moment and bearings seem ok although I did change it relatively recently. Just drill a drainage hole then? Should it just go right in the centre of the BB shell?

Clean it , then drill it, then douse it in ACF50 as stated.

Thanks guys, found an old thread on drilling drainage holes so will get to it.

Just drill a drainage hole then?

Yep. 5 or 6mm. Take the cranks and BB off and clean out all the metal bits.

Check the rest of the frame

Another thumbs up for acf 50.

If you can get a hand pump version that would be good as I find the aerosol can bog down a bit in use. For the seatstays etc. you could try some Scotoiler FS365 which is thinner/cheaper and you can probably use it to ‘fill’ the tubes to ensure the whole thing is coated. I’d then spray some acf in afterwards.

XCP

https://www.bennetts.co.uk/bikesocial/reviews/products/the-best-motorcycle-corrosion-protectants/tested-xcp-rust-blocker-corrosion-protectant-review

I’ve experienced rust down a steel seat tube like this but not quite as bad. That’s mingling down there :o) So at least you’ve escaped the stuck seat post which can be a ball breaker to remove. The last time I encountered this I cut up a length of mild steel rod ( a bit of wooden dowel would do) & jammed a ball of Scothbrite or green pan scourer in the end, mounted this in the battery drill and it gave the seat tube some reaming action. Took a couple of minutes but it very quickly gets rid of the rust.

@Paton has beaten me to the recommendation for the XCP Rust Blocker. If you’ve ever unwrapped a brand new industrial ball bearing from its wrapper you’ll recognise the smell straight away. Looks & smells like Cosmoline which has a proven track record. The XCP sprays on as a thin brown liquid and eventually forms a protective waxy coating that doesn’t wash off, very like Weagles Frame Saver spray but affordable. The ACF50 is great in applications where you don’t want to see it, IE on your motorbike but does get washed off despite what the marketing would have you believe. The XCP is in a different league provided the film doesn’t get breached.

Thanks Dave. I was quite shocked when I got the post out as the frame is only a year old. I’ve always had steel frames and never seen this level of rust. I’m thinking the culprit might be the dropper post port. There is a port for stealth routing but I’m running an external one as I just had it from my last frame and thought I’d run it til it died. I covered the stealth port with a good covering of gorilla tape but maybe damp is getting in, I then store it hanging from the front wheel so any damp might well be festering in there and draining into chain and seat stays. I’m sure with the steps described above all will be good though. Just going to order some XCP (linky)

Water usually gathers in chain stays and they rust inside-out – if there’s bubbling of the paint there it’s often not a good sign. Citric acid (or Coke) will help remove any rust and then apply suitable rust-inhibiter. A spiral wire brush fitted to an electric drill down the seat tube also helps.

@davesport had a quick look around and found a good review of rust preventers here

Looks like things have moved on in the 10 years since I’ve had a motorbike and XCP Rust Blocker is the new king!

Check the rest of the frame

Nice video!

He TIG welded the BB end but brazed the drop out end – is that just a strength thing?

or maybe just going for the original look, for a frame that he, probably, made himself originally.

I coat the inside of my old frames with one of the many available rust converters. Pour in, shake it about. Let it dry a couple of days.

I then add a coat of Bilt Hamber Dynax S-50 to finish. https://www.bilthamber.com/dynax-s50
It’s a light brown wax, one of the best in the business for protecting cavities on cars so makes sense it’d do a good job protecting cavities on a bike.
One aerosol bottle is more than enough for a bike, and comes with a long lance to get right along the top tube etc through the vent holes.