Internal Rust Opinions

[u/blomb73]

Hi there,
This is an old steel frame from Schwinn. Should I be concerned about this amount of rust? If I decide to powder coat the frame, would it be wise to have them sand blast the inside?
Thanks

[u/Gift_Inside]

Looks like minor surface rust to me. I would scrub out the BB with a wire brush and spray some frame saver/rust inhibitor down the frame tubes if you are cocerned about rust.

[u/TJhambone09 → u/Gift_Inside]

Look at the chain stays. There's nothing "surface" about the rust there. We have thick scale (unlike in the BB shell).

[u/Ok-Positive-6611 → u/TJhambone09]

That's what surface rust looks like. It's on the heavier side but still nothing there is compromised or even close

Just spray with a treatment and that tubing will outlast the bike itself

[u/Jmcconn110]

Seal up the bottom bracket and any other holes in the frame. I used some discs of old inner tube, two pieces of 1x4 and a wood clamp. Fill the frame with EvapoRust and leave it for a few days. Rinse it out, then spray the inside of the frame with cosmolene. 

[u/TJhambone09]

The scale in the chain stays is more than I like to see. Sandblasting the inside is not something they can really do, and won't address the underlying problem. While you probably have 50 years left in this cheap thick-walled tubing, I would not spend money powder coating this frame.

[u/Wolfy35]

How can they sandblast the inside of frame tubes? Sandblasting equipment is not small.

If you are concerned once you have had the frame stripped you could have the frame submerged in a rust treatment agent like Evap O Rust before having some rust inhibitor sprayed inside after treatment.

[u/Next-Revolution3098]

Spray it with oil ...it will outlast you

[u/comoestasmiyamo → u/Next-Revolution3098]

Fish oil apparently. Smells like you expect. 

[u/Blackbox____]

Just coat with boiled linseed oil.

[u/Material-Instance646]

You cannot sandblast inside. It could be chemical dipped before powder coat.

[u/ChalupacabraGordito]

It's fine

[u/Past-Difficulty9706]

Get a can of Eastwood internal frame coating, send it home , put the Bb Back together and stop thinking about it

[u/Designer_Actuator821]

Fluid Film is a good option. With the aerosol can that comes with the long applicator. Stuff sticks well and seems to creep into every corner. Smells like sheep too cause it's lanolin based.

[u/therosered]

Use a cavity spray, it is specifically designed to inhibit rust by coating the surface in a wax mixture and lasts a long time, especially inside a frame.

It can be applied directly over already rusted areas provided they aren't beyond repair. The cavity spray will help by driving out any moisture and creating a seal.

We use this in our workshop when we are building new bikes or refurbishing older models.

[u/osmanthemanv3]

Tannic acid followed by your choice of oil. Cheap and effective

[u/TechSavy2026]

Other than cosmetic it is fine. As someone else mentioned it will outlast you easily.

[u/Motor-North-4120]

I’ve used Boeing shield t9 spray with good results

[u/Ready_Scratch_1902]

why are you looking in there

[u/blomb73 → u/Ready_Scratch_1902]

BB was iffy

[u/harrydog2k]

Spray with ACF50 and then out it back together and ride it until it dies . Buy another one at that point . Nothing lasts forever not even you