Internal rusting on steel frame

[Dirk Van Der Dirk]

Hi all, newbie to the forum here!
I joined primarily for some advice about my 3 year old Fuji steel touring bike. Steel frame, steel seat post. When I took the seat post out last week I noticed rust smears on the post. Now I always use grip paste on my seat posts and take them out every few months to wipe down and reapply. This time I looked down the seat tube and noticed light rusting of the tube. Seat post not rusting just the frame. I have read that frame saver or boeshield spray helps protect tubes from further rusting. In people's experience am I worrying about nothing or should I address this? Thanks all.

 

[Cycleops]

Hello and to the forum.
Never seen a steel frame rust from the inside out, rust would always get hold under any poor paintwork on the outside. If it worries you use some rust treatment and then proof it.

 

[fossyant]

Steel can rust from inside out. But what you do is spray the inside of the tubes with GT85/light oil and or waxoyl. I always use grease for the seat posts as it stops water getting down, creating a seal. Hot-cold cycles (winter/house etc) can cause condensation.

BTW, I'm talking 3 steel frames I own and use that are over 30 years old and treated from new. Remove the seat post or BB, and there is an oily smell, and no rust.

 

[Ian H]

Waxoyl thinned with white spirit will work. Allow it to flow through the tubes, then drain. As above, lightly grease the seatpost. If it's a good fit you shouldn't need grip-paste.

 

[richardfm]

Grip paste is for seat posts in carbon frames. You need grease for steel frames, after you have applied Waxoyl.

 

[wafter]

Waxoyl thinned with white spirit will work. Allow it to flow through the tubes, then drain. As above, lightly grease the seatpost. If it's a good fit you shouldn't need grip-paste.

Nice idea - one assumes the white spirit eventually evaporates off and leaves a thicker / more solid coating behind...?

I need to do my Brompton but the lack of application method is a stumbling block...

 

[Dirk Van Der Dirk]

Thanks all. I have just returned from a mini dutch tour and before I left i made sure there was a decent amount of grip paste in the tube/post. I did think of spraying a bit of gt85 inside before I left. Will remove the post, give the inside of the tube a wipe, spray some gt85 inside and leave the seatpost out for a day or so. Will then wipe the inside of the tube, apply more grip grease/paste, put the seatpost back inside. Hopefully the gt85 wont lead to post slippage.

 

[midlife]

753 frames with their silly thin chain stays had a habit of rusting through near the BB area where water could collect.

First thing the owner knew was when it broke !

 

[raleighnut]

I wouldn't use grip paste or grease on a seatpost, Petroleum Jelly (Vaseline) is best. It prevents 'galvanic action' occurring as it is not conductive like grease is.

Grease is an emulsion of Oil and Soap, great as a lubricant but not good in a static application

 

[Chief Broom]

This post interests me as i intend to get a steel bike in the future and did wonder about internal rusting...I once bought a Suzuki GS550 [motorcycle] as spares /repairs, fixed the engine and all was going well until noticing some paint bubbling underneath the frame tubes. Poked it with a screw driver which went straight through the steel ...

 

[mickle]

What's it made of? If it's ChroMoly it's very resistant to oxidization. If it's mild steel it would benefit from some internal treatment. Concentrate on the chain stays, which is where frames tend to rust if they're going to.

My paint free mid 90's ChroMoly Marin lives outdoors 24/365. Once a year I wipe it down with Vaseline.

I don't know how much truth, but I read recently that early 1930's Fords were made from ChroMoly steel, which is why American hot rodders are still finding useable car bodies out in the wild.

 

[MichaelW2]

Water will always find a way in. You need to give it a way out. Many bottom bracket shells have a small hole at the lowest point. It acts as a drain hole and also the attachment point for screw in cableguides.
The chainstays may have small holes near the rear dropouts, from the brazing process. You can tip the bike to drain water out and squirt water displacer ( like WD40) in. Dont use WD40 if you have old style loose ball bearing BB spindle, it will dissolve the grease.
I used WD40 on a frame that lived outside and was ridden in coastal paths. No internal rust.

 

[Dirk Van Der Dirk]

What's it made of? If it's ChroMoly it's very resistant to oxidization. If it's mild steel it would benefit from some internal treatment. Concentrate on the chain stays, which is where frames tend to rust if they're going to.

My paint free mid 90's ChroMoly Marin lives outdoors 24/365. Once a year I wipe it down with Vaseline.

View attachment 736599

I don't know how much truth, but I read recently that early 1930's Fords were made from ChroMoly steel, which is why American hot rodders are still finding useable car bodies out in the wild.

Yes it is reynolds 520 chromoly tubing. Thing is, i barely ride it in the rain, however it is kept in my shed which is getting old and i do have to use moisture trap devices in the cold months which helps in my experience.

 

[Dirk Van Der Dirk]

Water will always find a way in. You need to give it a way out. Many bottom bracket shells have a small hole at the lowest point. It acts as a drain hole and also the attachment point for screw in cableguides.
The chainstays may have small holes near the rear dropouts, from the brazing process. You can tip the bike to drain water out and squirt water displacer ( like WD40) in. Dont use WD40 if you have old style loose ball bearing BB spindle, it will dissolve the grease.
I used WD40 on a frame that lived outside and was ridden in coastal paths. No internal rust.

Yes it does have said hole in the bb shell. It is a bb52 hollowtech type and a few months ago i took it out to check all was ok down there. No signs of rust. I barely ride the bike in the wet but the shed I keep it in is old and I have to use moisture traps in the winter as it can be a little porous, so to speak!

 

[Gillstay]

I tend to use Bilt hammer ferrosol as its also useful for other jobs and better than WH40 etc.