[Closed] Welding a steel frame

Folk don't do it generally so I guess it doesn't work.

Try something stronger? Checked your seatpost insertion?

I'd take the hint and get a stronger bike 🙂

Yea there was still plenty of seat tube in the frame will get something stronger but was looking at welding as short term solution till i get the cash for new frame

Welding it would be fine but you may need to get a gusset plate installed to give added strength.....

Get it down your local engineers, they'll weld it up no bother. Assuming its pretty ordinary steel it shouldn't be significantly weaker than it was before - can always get a muckle gusset welded on to be safe!

Just had a hole in my old steel Gios filled. I can't see how it can be any weaker a weld isn't like glue it actually amalgamates.

so, whilst staring at your handjob you found a crack!!! did you fill it? 😯

Just had a hole in my old steel Gios filled. I can't see how it can be any weaker a weld isn't like glue it actually amalgamates.

Weld geometry = stress riser. I agree that in this case it's likely to be negligible though.

welding can reduce the strength. The heat involved creates a "heat-affected-zone" around the weld and can make it weaker - geometry and material dependant obviously.

BUT it will be stronger than it currently is (with a crack in it 😯 )

Just get it welded. ER70-S filler wire is OK.

Are steel frames welded ?
I thought they were brazed.

Both. Traditionally they were brazed and often still are, mass produced frames tend to be welded. Tubesets can be specific to a type of construction.

To the OP, get it welded with an extra plate between the two tubes.

Welding can decrease strength, but any decent welder should be able to do it correctly so it doesn't significantly alter the original strength, this may include having to heat treat the frame to prevent it becoming brittle in the HAZ due to rapid cooling etc.

I don't think I would trust many welders to work on thin 853 tubes, and while the handjob isn't 853 I thought it was an Easton equivalent?

Its often repeated phrase that steel frames are best for touring because they can be fixed anyware, but I don’t think its actually true with modern tubing, welding them has become a much more specialised job. I read an interview a few years back by an American frame builder who said that most of the welders he interviewed just weren’t up to the job, they were massively experienced working construction, cars and oil pipes etc, but just couldn’t do delicate work.

That's what I was thinking. If they are welded, I would suspect it is gas or tig on a quality frame.
I wouldn't want to trust the average mig welder to repair a Reynolds (or equivalent) tubed frame.

http://reynoldstechnology.biz/faqs/welding_joining/1

"For many years the only recommended way to assemble a frame was by fillet brazing or brazing with lugs, and this was the way 531 frames were constructed. When Reynolds introduced 753, due to the nature of the material, these tubes needed to be low temperature silver soldered.

We now have a new generation of materials in 525, 725, 631, 853 and 953 steels. All of these can be brazed, but the most popular method of assembly is by TIG welding. (on 853 we do recommend that gear fittings etc are silver soldered onto the tubes).

There are many filler wires that can be used on 525/725/631/853 like ER-70S-6. "

http://reynoldstechnology.biz/our_customers_motorcyclists.php

http://reynoldstechnology.biz/our_customers_sports_cars.php

"Capable of being repaired using TIG/MIG welders and recycled as normal for steel."

Curtis braze their tubes.
http://www.curtisbikes.co.uk/info.html

If your looking for something stronger T45 will do the job.

"Capable of being repaired using TIG/MIG welders and recycled as normal for steel."
That's referring to a car chassis though.
I still wouldn't want to trust the average car mechanic who is used to welding new sills on old cars to make a good job of the wafer thin tubes used on a bike frame.

I don't think I would trust many welders to work on thin 853 tubes, and while the handjob isn't 853 I thought it was an Easton equivalent?

for anyone near East Grinstead, then a company called Exact Weld do super precision welding - like stuff for superbikes, medical, mod etc etc - i have had al sorts of bits welded by them up from little bits of pipework, to from scratch alloy petrol tanks and sumps etc - welding is top notch.

Are bike frame materials all essentialy Cr-Mo steel?

If so, it's easily weldable. Just ensure that the area is preheated (100°C should be enough). It'll probably screw up the paintwork though.

no warranty i guess, pity cos cove charge enough in the first place..

i cracked my old alloy GT avalanche just behind the head tube on the top tibe and got it welded - it became my trusted commuter till it was pinched - no stress for short term i'd say, especially as steel is even easier to weld.

As above - you can weld or braze it.

Brazing will involve less heat but maybe over a bigger area than TIG, so will probably give less distortion but more paintwork damage. You can bung a lump of steel in the seat tube if welding to act as a heat sink, but it may get stuck due to distortion etc....

If it were mine I'd drill both ends of the crack, braze it (brass will run into the crack if it is well fluxed and clean enough) and then braze a little plate / sleeve / gusset or something over the top. Then carefully use an expanding reamer to clean up any slight distortion in the seat tube bore. Any crack / repair in that area of the frame isn't likely to result in sudden failure anyway.

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This was just mig welded, there was a hole about 6mm dia from drilling out the post. You can just see the plug under the lug. Just needs tidying up now.
Should see me another twenty years.
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