The Condition: Muchoo Rusto Infestation
The Differential Diagnosis: Swiss Cheesy tube condition requiring immediate attention, skill, and a lot of patience.
Mike had found a classic gem, an 83 Fat Chance mountain bike, that had lingered unloved for decades and wanted to have it checked out, spruced up, and built to be a casual Central Park ride with simple distinction and history.
The Fat came to the shop shod in an industrial black powder coat that had taken it's share of wear through the years. Now, if you've been following the blog for any length of time, you know my opinion of Fat's penchant for sealed tube construction (it blows!). Couple that with a finish that is basically a plastic shrink wrap around the steel and you've got a tight package that leaves moisture no where to go...but through the structure.
When I stripped the Fat it had a solid patina of rust that has been allowed to develop due to the single coat of powder. Quite scary and oh so ugly, but what to do?
CAUTION, rant ensuing...Liquid finishes utilize a primer layer that protects the sub structure from this fate chemically, providing for long term protection. Until recently, no such option existed for our powder brethren, leaving those steely frames destined for a premature death. If y'all are powder coating your frames, please take note that this too will be your fate unless you invest in the new powder primer layers. These primers add to the cost, but increase the potential life of your product ten fold. I personally want my bikes to be around long enough to pass on to my customer's grandkids...if you are a builder who is coating with powder and not using a primer layer, shame on you. Your customers deserve better.
Anyhoo, back on track. Once in the blaster, I began to hit the frame with a fine grade Aluminum oxide media, strong enough to take off the decay but fine enough not to blow through the tubes. Here you can see the difference the blasting makes...
Once the patina of rust was removed, the diagnosis was not good. I counted 16 holes in the down tube and seat tube that were full thickness and gaping open. Unfortunately, many more were ready to break through with a little picking. Yikes!
A quick consult with Mike as to his intentions for the bike would be necessary to determine what course of action was to be pursued; major corrective surgery with the tig torch or a tube ectomy and replacement. After some emotional communication in the "waiting room", it was determined to save what we could and get the old girl back on the street.
The work began...all the holes were drilled out to fresh metal devoid of rust. This was no small task, as some of the holes ended up being almost .25" in diameter, a gaping hole when you consider the need to close it. I had hoped originally to use silver for the process, but the gaps became too big to jump the material across and retain the necessary strength.
Once the rust was all cut out, it was time to attack the "rattling thingies" in the downtube. Here's what I found...
Lot's of bits of rusty material. How many is lots? Take a look below, this is just one of three piles I accumulated in the 2 hours of jiggling and shaking (yep, you read that right, 2 hours...boy did that suck)
With as many "rattlies" out as I could, it was time to prep for welding. Here's a shot of the down tube before it hit the table...
And through the magic of the Internet, I've closed up the holes and am part way through the process of cleaning up the tubing. Not magic really, I just got so focused I did not take any pics...sorry. In this shot, I've done the rough sanding and am getting ready to get serious about the fine details...
I had originally hoped to paint the whole frame, bar, and box crown fork today, but the emergency rust correction took the majority of the day. Regardless, I was able to get three coats of primer down. I'll sand it one more time in the morning and then start shooting a nice deep red on all the parts.
I enjoy reviving cherished frames and sending them back to their owners fresh and ready for lots of miles, but I gotta be honest, it's a money loser every time. The amount of time invested in the process far exceeds most folks desire/willingness/ability to pay. If not for the love of the game from both parties, many of these projects would never happen. So, it's a win/lose situation. Emotionally, it's pretty darn cool, business wise it's a poor path to trod.
I'll shoot the color tomorrow and post up some pics.