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-   -   Top tube dent repairable? (https://www.bikeforums.net/showthread.php?t=1194437)

52telecaster 02-22-20 12:34 PM

Top tube dent repairable?
 
This is a 72 paramount frameset. Just wondering if there is any way to ameliorate this dent. I dont have the bike yet.
https://cimg6.ibsrv.net/gimg/bikefor...5fcb9a367.jpeg

The Golden Boy 02-22-20 12:39 PM


Originally Posted by 52telecaster (Post 21338151)
This is a 72 paramount frameset. Just wondering if there is any way to ameliorate this dent. I dont have the bike yet.

Send an email to Andy at Yellow Jersey.

He'll ask for pix and dimensions (or just send them with the email). He was confident he could remove the dent from my Voyageur SP. It still makes me sick to think of that dent.

unworthy1 02-22-20 01:41 PM

Yes, with the correct "re-forming blocks", greased up, clamped in a well-anchored vise and then plenty of elbow-grease applied. But you will lose some paint. Another approach (may work fine since a dent in that location usually is strictly cosmetic and will not affect frame alignment or performance): just remove the paint in and around the dent, fill with your choice filler (I like epoxy putty, sand down until perfect and touch up/blend paint, or cover with a painted band, bar or graphic...a matter of personal choice and style.

52telecaster 02-22-20 01:44 PM

Thanks guys. Looks like the paint sucks there anyway.

Chuckk 02-22-20 04:44 PM

If you try to fill it without using the blocks first, you;ll find that the "downhill" sides stick out.

tyler_fred 02-22-20 05:00 PM

I’ve wondered if a stud welder and dent puller (think auto body shop) would work?

Chuckk 02-22-20 07:20 PM

https://www.bikeforums.net/classic-v...ube-dents.html

gugie 02-22-20 08:29 PM


Originally Posted by tyler_fred (Post 21338420)
I’ve wondered if a stud welder and dent puller (think auto body shop) would work?

T​​​hinwall tubing, maybe (?), but there's much easier ways already posted are the way to go.

I have aluminum frame blocks to use for this. A hardwood block cut through with a Forstner bit then cut in half would do the trick as well. It won't completly remove the dent, but will minimize it, make the tubing round first, then fill what rolling the dent won't.

JohnDThompson 02-22-20 09:02 PM

Repairable? Certainly.

Worth the cost and bother? That's up to you.

Hudson308 02-22-20 09:07 PM


Originally Posted by tyler_fred (Post 21338420)
I’ve wondered if a stud welder and dent puller (think auto body shop) would work?

I wouldn't use a Fitz-A-Dent on bicycle tubing. The tubing is pretty thin, and the spot welding process may alter the temper of thin, higher-quality tubing (531 or Columbus).
I've rolled the dents with aluminum frame blocks on a couple frames now, with mostly satisfactory results. The dent won't go away completely, but with a little JB weld as filler carefully feathered, it disappears under powdercoat.

easyupbug 02-22-20 09:23 PM

I have seen and now own a head tube rolled by Andy Gilmour and then brazed to fill and it is perfect, not cheap but for many frames in my opinion they are worth it, beyond $ and ¢.

gugie 02-22-20 09:44 PM

If the frame were going to be repainted anyway, fixing the dent is a no-brainer. If not, it's an expensive cosmetic fix. If you're handy with an aerosol spray can, you could do this as a DIY project.
  1. Roll out the dent as best possible - see the link Chuckk posted above. As noted before, you can make frame blocks out of hardwood and a forstner bit. It won't be quite as good as aluminum frame blocks, but it's a zero cost option for people with a few woodworking tools.
  2. Sand inside the dent and around it to bare metal.
  3. Fill with JB weld, or some other epoxy based filler. Let it harden per instructions (typically a day), carefully file then sand down flush.
  4. Generously sand around the damage
  5. Primer
  6. Paint
To match the paint, automative shops can "paint chip match" to closest color (out of thousands) and make up a spray can for you. Last time I did this it was around $20. If you want an exact match, leave the frame with them and expect to be charged 3-4X as much. Properly done you can get it to 10 foot distance match or better.

I fill dents when the frame is getting other work - repairs, 650b conversions, etc. If you're powder coating, I use silver or brass to fill the dent on the recommendation from Groody Brothers. They've found that sometimes epoxy based filler outgasses when you're heating up the frame to powder coat temperatures.

SurferRosa 02-22-20 11:18 PM

Keeping something like a '72 Paramount as a beater can be a good thing...

52telecaster 02-23-20 02:18 AM

You guys are inspiring. When i pick it up i will post more pics. I want to set this up as my around town bike. It is coming with honjo fenders and an old schwinn saddle bag. Nitto north road style bars as well as the original seatpost, crank and a brooks.

https://cimg7.ibsrv.net/gimg/bikefor...994778813.jpeg
Currently set up as a three speed
https://cimg8.ibsrv.net/gimg/bikefor...be1657e72.jpeg
Serial no.
https://cimg9.ibsrv.net/gimg/bikefor...50242bdca.jpeg
Bag

52telecaster 02-23-20 02:21 AM


Originally Posted by Chuckk (Post 21338564)

very inspiring thread!

52telecaster 02-23-20 02:25 AM


Originally Posted by gugie (Post 21338722)
If the frame were going to be repainted anyway, fixing the dent is a no-brainer. If not, it's an expensive cosmetic fix. If you're handy with an aerosol spray can, you could do this as a DIY project.
  1. Roll out the dent as best possible - see the link Chuckk posted above. As noted before, you can make frame blocks out of hardwood and a forstner bit. It won't be quite as good as aluminum frame blocks, but it's a zero cost option for people with a few woodworking tools.
  2. Sand inside the dent and around it to bare metal.
  3. Fill with JB weld, or some other epoxy based filler. Let it harden per instructions (typically a day), carefully file then sand down flush.
  4. Generously sand around the damage
  5. Primer
  6. Paint
To match the paint, automative shops can "paint chip match" to closest color (out of thousands) and make up a spray can for you. Last time I did this it was around $20. If you want an exact match, leave the frame with them and expect to be charged 3-4X as much. Properly done you can get it to 10 foot distance match or better.

I fill dents when the frame is getting other work - repairs, 650b conversions, etc. If you're powder coating, I use silver or brass to fill the dent on the recommendation from Groody Brothers. They've found that sometimes epoxy based filler outgasses when you're heating up the frame to powder coat temperatures.

what is a good source for the frame blocks? I have an excellent vice. I am assuming i need 1 inch blocks for a 531 top tube?

daviddavieboy 02-23-20 05:39 AM

I have fixed many but keep in mind that if you plan to powdercoat in the future brazing or metalab must be used.

Chuckk 02-23-20 09:32 AM

Doesn't have to be powder coat, paint works just fine. If the rest of the paint job is acceptable, you can even paint just the tube between the lug edges.
A buddy did that to a Schwinn which we rolled that somebody had wacked along the top tube five or six times.
Testors orange spray matched exactly, and you can't tell that it ever looked like a zipper.

Doug Fattic 02-23-20 09:32 AM


Originally Posted by 52telecaster (Post 21338820)
what is a good source for the frame blocks? I have an excellent vice. I am assuming i need 1 inch blocks for a 531 top tube?

Dave Bohm used to sell wood frame holding blocks but I don't know if he still does. The aluminum blocks are sold by Paragon Machine works that makes frame building bits and accessories. I've made my own wood blocks. If you can do that I can provide instructions.

A wood block is one of the basic tools every frame builder needs to own. It is how you hold a frame while working on it in a vise. In the picture on the left is the 1" wood block I use when a frame building class student is holding something to be brazed. Often their beginning torch handling skills lets the flame wander way off target and the wood block can suffer. The next block is for them when they are filing. Old broken-in blocks have just the right amount of stickiness to hold a position but still able to move without changing the vise clamp pressure. The 3rd from the left is my personal one I usually put away when students come so it doesn't get more damaged. The aluminum one I bought from Paragon Machine Works.

If I am taking out a dent, I start with the wood blocks that are a bit more forgiving. After that I use the aluminum one to get it as round as possible and finally I add some silver that isn't designed for strength but will fit a dent nicely. I got it from Cycle Design. When I was learning to build frames in England many years ago we often got frames in for repair and repainting and it was common we would fill dents with brass (actually bronze but in the States we call is brass).
https://cimg2.ibsrv.net/gimg/bikefor...62511b194b.jpg

Hudson308 02-23-20 07:35 PM


Originally Posted by 52telecaster (Post 21338820)
what is a good source for the frame blocks? I have an excellent vice. I am assuming i need 1 inch blocks for a 531 top tube?


Originally Posted by Doug Fattic (Post 21339050)
The aluminum blocks are sold by Paragon Machine works that makes frame building bits and accessories. The aluminum one I bought from Paragon Machine Works.

I bought my aluminum blocks from Paragon, as well. Dirt cheap IMHO.

Hudson308 02-23-20 07:51 PM


Originally Posted by gugie (Post 21338722)
I fill dents when the frame is getting other work - repairs, 650b conversions, etc. If you're powder coating, I use silver or brass to fill the dent on the recommendation from Groody Brothers. They've found that sometimes epoxy based filler outgasses when you're heating up the frame to powder coat temperatures.


Originally Posted by daviddavieboy (Post 21338847)
I have fixed many but keep in mind that if you plan to powdercoat in the future brazing or metalab must be used.

I don't choose to disagree with you lightly, Gugie. You're a world-class craftsman in my book, and you're one of the few guys who are actually doing this stuff.

If you're doing a restoration on a premium or historically significant frame (like a Paramount), then by all means have a frame builder fill the rolled remains of the dent with silver or brass. It's the best way to fill a dent in bike frame tubing, period. That's what I did with my '29 Cyrus-Great Western.

However if you're working on a budget to get a decent classic frame presentable again, you can indeed use JB Weld under powdercoat (or paint). It holds a static charge like metal, and holds up just fine to the 400 deg. F used for most powdercoating.
I've done a couple of frames this way with very nice results. More importantly, my powdercoat guy has done dozens. He's also filled sizeable dents in motorcycle tanks this way as well. I don't know what type of epoxies Groody Bros. has had trouble with, but I haven't seen any.
https://cimg4.ibsrv.net/gimg/bikefor...ac8460b552.jpg

Kuromori 02-23-20 08:04 PM


Originally Posted by Doug Fattic (Post 21339050)
When I was learning to build frames in England many years ago we often got frames in for repair and repainting and it was common we would fill dents with brass (actually bronze but in the States we call is brass).

Oddly enough, LFB/Sifbronze is actually brass if you go by the tin/zinc distinction but it's called bronze by tradition.

gugie 02-23-20 11:53 PM


Originally Posted by Hudson308 (Post 21339950)
I don't choose to disagree with you lightly, Gugie. You're a world-class craftsman in my book, and you're one of the few guys who are actually doing this stuff.

If you're doing a restoration on a premium or historically significant frame (like a Paramount), then by all means have a frame builder fill the rolled remains of the dent with silver or brass. It's the best way to fill a dent in bike frame tubing, period. That's what I did with my '29 Cyrus-Great Western.

However if you're working on a budget to get a decent classic frame presentable again, you can indeed use JB Weld under powdercoat (or paint). It holds a static charge like metal, and holds up just fine to the 400 deg. F used for most powdercoating.
I've done a couple of frames this way with very nice results. More importantly, my powdercoat guy has done dozens. He's also filled sizeable dents in motorcycle tanks this way as well. I don't know what type of epoxies Groody Bros. has had trouble with, but I haven't seen any.

That's pretty wise counsel. It's not a whole lot more work for me to fill using silver or brass, whereas just about anyone can mix up some JB Weld and apply it. I too have filled several frame dents with JB Weld with no issues, so for most people and most frames, have at it. The worst thing that can happen is some irregularities at the site of the dent.

gugie 02-23-20 11:59 PM


Originally Posted by Chuckk (Post 21339049)
Doesn't have to be powder coat, paint works just fine. If the rest of the paint job is acceptable, you can even paint just the tube between the lug edges.
A buddy did that to a Schwinn which we rolled that somebody had wacked along the top tube five or six times.
Testors orange spray matched exactly, and you can't tell that it ever looked like a zipper.

That's a good trick. Even reasonably experienced DIY house painters know that if you get paint that's a close match, don't just paint a patched area, paint the entire wall. The difference in lighting will make it unnoticable.

52telecaster 02-24-20 04:00 AM

I'll order some blocks and get it in a little better shape than it is now. Ty everyone!


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