Randybb

I suffered a house fire last month, and somewhat miraculously managed to pull my vintage Columbus SL steel frame bike out of the ruins relatively unscathed, just incredibly dirty and with totally shot hub bearings.

The blast from fire hoses pushed it from a fairly safe area towards the fire and eventually buried it under a pile of charred wood and debris. It looks like a couple spots on the frame came into contact with hot coals, one on the fork and one on the top tube. The paint is blackened, but it looks like the chrome plating underneath the paint is still in tact as far as I can see.

See the attached picture. The dull grey/brown color appears to be burnt paint, and the shiny grey color is the chrome plating underneath that. The whole frame appears to be chrome plated underneath the paint. The damage on the top tube is very similar.

My question is then, can we determine how hot the tubing got at these locations and if that's anywhere near how hot it'd need to get to weaken the steel? I want to put this bike back together but don't want to get hurt riding it...

cpach

If the paint is mostly intact I'd be unconcerned about the well being of the steel. I'm sure it underwent more intense heat cycles during brazing. My concern would be for the brazing material in the lugs, but considering the relatively light damage to the paint I'd also bet it's okay. I'd look over the lugs pretty carefully to see if they've lifted or formed any gaps anywhere, and maybe check frame alignment. I bet it's fine.

Ronsonic 

I cannot imagine that that was enough to damage the tubing or compromise the braze. When you sand it down take a good look. Bet you don't even see discolored steel.

ramzilla

Call me crazy but try this test: Tap the frame with a stick. Listen to the sound. SL frame should produce a nice ringing sound. If metal has lost it's temper will make a dull sound.

CliffordK

Doesn't the sanding take off the blue? One of the colors steel will turn is a golden brown, which may be difficult to distinguish from the burnt paint. Nonetheless, the damage appears to be minimal.

Perhaps before doing a full repaint, carefully inspect the lugs. then reassemble the bike and see how it rides.

Mr IGH

I'd ride it, that fork tip was red hot when they brazed the dropout into place.

fietsbob

Yea, the Brass that holds the fork tip in, would melt first, and the paint over the brass, there, is still intact.

pwyg

To do any damage to the steel the heat would have incinerated the paint to bare steel I doubt if the heat got above 400 degrees from what i see. The chrome is not even discolored which happens at temps well over 500 degrees. The bronze will not go liquid until 1700+
Paul

Seizedpost

What's wrong with the hub bearings, heat damage or water damage?

CliffordK

Charred Grease?

If the fire/heat wasn't too bad, it might be interesting to try to clean it all up.I'd probably make sure all parts are loose... better early than late. Clean off oxidation from threads, and grease up anyplace that might seize.

Depending on the bike, you could even leave a few signs of "battle damage".... It could make for some fun stories Light buffing + clearcoat?

3alarmer

.
...your bike is fine. Really. If you had a house fire you have things to worry about, but the bike frame's integrity is not one of them.

Moe Zhoost

I did more paint damage using a heat gun on a frozen bottom bracket. From the look of your fork, I doubt that it got over 900 deg. F. You were lucky, at least as far as the bike goes. Hope you didn't lose a lot.

Good luck.

Homebrew01

Ditto... bike is fine. Hubs probably just need fresh grease.

bulldog1935

I'm a metalurgist, licensed PE and analyze fire damage all the time - that's only seen 500oF, which is not enough to alter the steel or even the braze.
(I earn my bread and butter with life prediction at 1000-1800oF)

The bearings should be fine, too, but the grease is gone.

_ForceD_

Personally, I think it's cool to show battle scars. I'd just clean the frame really well and then just ride how it is (of course other components will need attention). Might even put a varnish coat over it to protect from further oxidation.

Dan

WizardOfBoz

Good advice. From one PE to another, though (especially if you deal with temperatures all the time), you can get the degree symbol, "°", by holding down the alt key and using the numeric keypad to type 0176. I think you probably know this, though, but it might be useful for others.

It's going to be above 90°F here in Philly next week. 88° today.

spdracr39

I would be more concerned about warping not weakened metal.

_ForceD_

I live at 41º north latitude 71º west longitude. Cool! On Macs it's just the alt and 0 (zero) key.

Dan

HillRider

Great to know. I have a Mac and I've been using the "Emoji & Symbols" menus to get to the degree and similar symbols. That will simplify at least one of them. Incidentally alt plus 2,3,4 and 5 give a superscript TM, a pound sterling, a cent and a infinity symbol. I expect there are others.

Moe Zhoost

I'd think that any warping would be fairly obvious. If the wheel goes into the fork ends normally and looks well aligned then there is no worry.

davidad

To do damage you need to take it well above 1200F or a dull red. A few hundred degrees more and it becomes easy to bend. I don't see that the part you showed would have been that hot.

Randybb

Thanks for all the insights folks. I'm feeling confident in the bike at this point. I carefully inspected all the lugs and everything looks perfect. I checked the frame alignment as best I could, everything is good. I've spent several days just disassembling every little component and screw and cleaning mountains of black gunk off of everything. Still waiting for the new cartridge bearings to come in -- I had recently upgraded to some modern alloy wheels. The wheels were pretty crazy looking, the plastic nut on the QR skewer from one wheel melted, front tire had a bunch of holes melted through the sidewall (brand new tire dang it....) and there was melted plastic burned onto the rim that I had to scrub off. No visible damage to the actual rims or hubs though.

One last thing, anyone have a recommendation for patching up a tiny little tear in the skin of my saddle? It's a Specialized power saddle. just a tiny little rip -- superglue maybe?