My Pompino has failed at the junction of the seat tube and botton bracket (there’s a hairline crack making its way around the joint). It looks like rust penetration from water getting in the seat tube.

I want to try and save the frame. I have access to a mig welder and brazing equipment

Any thoughts on if I could bodge a fix with either of these methods? I don’t care how pretty it looks, I need to save money as I can’t really afford a replacement frame!

Cheers

It looks like rust penetration from water getting in the seat tube.

How would that cause a crack in the weld on the seatube?

How old is it? seems stange to fail there with no reason??

Have you spoken to On-One about it?

How would that cause a crack in the weld on the seatube?

Maybe not? My reasoning is that any water will collect in this area, and the weld is the weak point? Willing to be convinced otherwise. 🙂

Picture of crack

I have approached On-One. I’ve had the bike seven years, so it’s out of their two year warranty period. They have offered me 10% off a new frame (currently £200). But as they don’t make a 135mm spaced frame at the moment, I’ll also need a new wheelset (so a £300 fix).

I’ve been keeping my eye out for a second hand frame, but no 135mm large or extra large have come up.

the weld has failed you could mig it up but it would be ugly but you could use a dremel after and clean it up.
thwang

would be better with a tig set

As it looks like it’s just gone at the weld & I double that’s rust related you could probably get away with a nice big fillet braze repair there. It takes a bit of practice to get good fillets though if you’ve not done any frame work before.

Where am I likely to find someone with a tig welder – car garage?

I’d advise a fillet braze by the sounds of things…Can you show a pic? Can give you some instructions how to do it too…This is one of the great things about a steel frame, they are highly repairable, easily another 7 years outta that frame..Brass is farely easy to work with too..Really wouldnt advise mig..

Ray “)

That would be great if I could get another seven out of it – it’s far too young to retire off!

I brazed a new drop out onto a frame 20+ years ago following an intraction between the derailleur and back wheel. Seemed to go ok, but any advice you can give would be greatly aprreciated Ray!

Picture here – CRACK

The crack goes almost all the way around.

HEllo rustychain, steel frames can go and go… I started writing you a lengthy description of what to do and then it just seemed crazy to explain fillet brazing if you’ve never done it…Its farely easy when you have! So I’ll ask you have you experience working with metal generally and are you determined to do it yourself or would you consider getting someone who really knows what they are at? I’d do it for you if I was anywhere near you which I assume Im not(Im in Sweden!)
Its a farely quick and easy job for a framebuidler, is there anyone near you that could give you a quote? Are you on a serious budget?
Do you have access to oxy-acetylene?

Ray 🙂

I much prefer to have a go myself – more satisfying! 🙂

I did metal work at school and know the basics of welding/brazing, but wouldn’t claim to be proficient. I have access to oxy-A.

I presume it’s a case of:
– throughly clean the area to be brazed
– flux up the area
– fire up the oxy
– heat the area
– feed in the brazing rod
– continue to heat the area for a short time
– rotate the frame and do the brazing in sections
– leave the frame to cool (or quench in water?)

Any major concerns about the above approach?

I’ve just emailed a local frame builder to see if he’d oblige with a repair…

Sean

Common fault with pomps. I know of quite a few that have failed there

Common fault with pomps. I know of quite a few that have failed there

I’m not that surprised to hear that. I’ve had nothing but problems with this bike. Not going to be buying an On-One again in a hurry.

Sounds like it’s worth repairing yourself – and not spending the £ on a pro job unless you **** it up.

All you need is flux and a rod – ceeway?

Sorry Rustychain, wasnt able to get back till now..I agree DIY is very satisfying, Im the same..
You’ve got your check list right just dont quench in water! 🙂
Another thing to be carfull of is over heating the join its really easy to do..Its a kind of game of flicking the flame on and away to keep the temp in the right area.
Afterwards you’ll need to soak the area in a basin of warm water over night to get the flux off..Can be a bugger that flux..
It would be well worth doing some test brazing on some thinish wall steel plate or pipe…try joining a few bits together, building fillets..It will pay off to spend a day just brazing everything you can find and get the hang of the heat control as much as possible.
Also build up a decent fillet..It is often a good idea to do a lightish pass first to fill the crack and seal the join…then go back and build your fillet…Afterwards you can clean it up with a suitable round file and sandpaper..*BUT BEWARE* Treat cutting into the tubing with the file like cutting into your own finger! its worth wraping the file in sand paper to avoid biting into tubing..That tubing is probably less than a mill thick so a single over zealous slip of your file can do some serious damage(believe me I know 😳 )

Best of luck and most of all enjoy the process..
Ask more questions if you like..Show some photo’s as you go!
Take it easy!

Oh yeah Ceeway is good for Brazing supplies for frames.

Ray

Have a go at brazing it, TBH you can’t really balls it up. I wouldn’t worry about filing it down. its not the most prominant stop

Thanks everyone for the help, tips and heads up about Ceeway – never heard of them!

I’ll give it a go and post up how I get on. Even if I mess it up I’m no worse off! 🙂

One thing is puzzling me. When building up fillets, what stops the smaller fillet from melting? I’m guessing that the trick is not to over heat the fillet?

Practice! 😉

Isn’t TIG used for alloy welding…

Using the term alloy when you mean ally should be a crime punished by death

Tig wields are used on steel frames as the heat from mig wields will blow through thin steel very quickly. That’s why tig and brazing are the most common ways to make a steel bike.

To removed the flux boil the kettle and pour the hot water over the flux. You can also get a flux which is for steel. Have a looks at little fish bikes? A ozzy bird that solders/brazzers bikes together its a great website.

thepodge – Member
Common fault with pomps. I know of quite a few that have failed there
POSTED 4 DAYS AGO # REPORT-POST

I’ve never heard of it before. I will go talk to returns.

Anyhow, OP… The swapout Kaffenback will work for you. 135mm spaced.
£99 ok?