Rusted Seat Tube - IF Deluxe

northerndave

New member
Hi everyone, preverbal rust question coming up. Not with a Fat though but an IF. I've recently picked up a 98 deluxe via eBay. Right at the bottom of the seat tube and I mean right at the bottom down on the reward facing tip of the tube between the chain stays the paint it's bubbling, not veins but i guess a 5mm diameter patch. The paint isn't broken. It's unlike others i've seen where rust develops in a ring around the tube about 5-10mm from the bottom. When i first inspected the inside of the tube looked pretty rusty and has now been wire brushed close to clean metal and Waxoyled. Without and endescope I can't really tell how bad it is down there. A fair amount of crud came out when I cleaned it out, all dry though.

So my question is how terminal is this do you think this is given the location? If it was further away from the weld and covered more of the circumference of the tube i'd think it was all over. I know in an ideal world I should get a new seat tube in there but I'm not sure it's economically viable to pump another $200-300 into the frame. Thoughts, experiences, good news, bad news - hit me with it
 

yo-Nate-y

Moderator
Staff member
I'd ride it but keep an eye on it. It sounds like you've done a good bit to slow further problems.
 

I-ROBOT

Member
Definitely keep your eye on it. I would even think about coating the exterior affected area with something to seal the paint. Even though you say its not broken, chances are (all puns intended) there are microscopic openings where moisture can attack and cause further damage. the heat-affected zones of 4130 tube welds are more susceptible to corrosion than the base metal since the steel frames are not heat treated after welding. This means the areas right next to the welds are most vulnerable. Inspect regularly and if you ride in the wet, clean and dry the area immediately including removing the seat post and making sure the interior of the tube is dry. Moisture accelerates corrosion - always

It is not likely that the stresses induced from riding alone would make the situation any worse. Just inspect after every ride in wet conditions

Good luck
Scott
 

northerndave

New member
Thanks for the advice Scott. It's gonna be under my watchfull eye. If had a quote for a new 835 seat tube coming in at about $130 + paint. I think I'll give it a few months of riding. If it's a good rider I'll invest in the work. Just had a 94 Shock A Billy arrive which has diverted my attentions somewhat.
 

Dr S

New member
Chances are you won't need a new tube Dave. My Yo had similar issues which i repaired 9 months ago. I'm also restoring JMCs Salsa with a similar problem.

Give me a shout if you want me to fix it up.
 
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