Thread: Bending steel bar - is a Bullfinch autotorch a good way to go?

I want to bend up some 5mm (or even better, 6mm) x 32mm steel bar to make a wheelbarrow undercarriage. There's some slightly compound angles, some wider radii and most of it is not 90 degree bends.

Probably not the right project for a beginner like me, but there you go. Anyhow, if I get a Bullfinch autotorch, which is more powerful than a Primus/Seivert torch, is that going to be a good tool for this job?

I own a Bullfinch and while it is a good unit it can have some shortcomings especially if the burner (selected or supplied) is too small.

There are 3 sizes so make sure you ask for the largest size when ordering.

Peruse the catalogue and you will find the right one. I think it was No 4105 but you had best double check that.

Grahame

Originally Posted by Grahame Collins

There are 3 sizes so make sure you ask for the largest size when ordering.

Yes, ok. Well, I had been thinking of taking up a current eBay offer that gets $60 discount, from Hampdon who seem to be a main retailer of Bullfinch in Aus.

https://www.ebay.com.au/itm/111737479510


But it just comes with the medium burner.

if the radii are large I'd be thinking of a bar bender...if short the bull finch would do it in time.... better an oxy acet or even charcoal pit/forge or whatever

Originally Posted by eskimo

if the radii are large I'd be thinking of a bar bender...if short the bull finch would do it in time.... better an oxy acet or even charcoal pit/forge or whatever

The radii are all different - there's the large radius at the foot, and the two sharp bends up where the stand bolts to the handles. Then a couple of slightly less sharp of bends to make the tie strap across the handles in front of the wheel.

A quick look at a bar bender on the Machinery House catalogue suggests it can do that -- but I don't know how much use it would get, whereas I can think of multiple uses for a Bullfinch torch as a hard bronze brazing torch.

While oxy would be ideal I can't see myself getting involved with that. Same with a forge -- some bridges will remain uncrossed.

Well anyway I asked the retailer if they'd swap out the medium burner in the kit for a large burner, at that price. Yes, they said.

But here's the thing (a question here) ... I still want to use that kit mainly for brazing light metal frames -- like, 30x30x2 angle to make, well for starters a frame for my air compressor hutch. So I don't want to find that the large burner is too much of a brute for those kinds of jobs. OTH, if I get the medium burner, will it still bend that 32x6 or 32x5 flat bar? Obviously if I was flush with cash I'd just buy the lot. But that's not the case. It all has to be make do and compromise. But still actually work out.

I converted an old builders barrow ( council cleanup throw out) recently into a moveable planter for the warrigal greens which is taking over our vegi patch.
I just used a big hammer and the 6” offset vice to tweek the steel undercarriage.
I have found a length of gal water pipe or a giant shifter handy in the past for crude flatbar bending.
If you are just resurrecting a barrow for use my mate in Canberra gets them from the big green shed recycling there in ACT.
He must have about a dozen, gave me one last time I was there with the ute.
H.

Originally Posted by clear out

If you are just resurrecting a barrow for use my mate in Canberra gets them from the big green shed recycling there in ACT.
He must have about a dozen, gave me one last time I was there with the ute.
H.

That's where my current wheelbarrow came from. Served me well but the tray has rusted through now. So I just got a galvanised Moss tray new, was going to put it onto the old undercarriage but it didn't quite fit, and anyway I was impressed by the solid frame on the Moss product -- so I thought I'd copy theirs more or less. I also bought a 140x42 length of merbau and cut that into two new handles. Keeping my aftermarket no-flat wide barrow wheel though.

Maybe I don't need to overthink the burner size on the torch if you can just bash the bar into shape -- but its always nice to have the right tool for the job.

Crikey that kit is a bit pricey!
I've got a BOC brand air/LPG torch, I reckon I was in for half that. I've got mine specc'd with the 50mm burner, good for IIRC 6kg of LPG consumption per hour- AKA shiploads of heat. It is compatible with the smaller Sievert air/lpg tips of a more modest size if that's your thing.
A brazing hearth of brick or similar would probably go a long way to getting the heat in where you need it with a smaller torch, if time is on your side. Otherwise oxy/acet would be the go in a perfect world.

Originally Posted by Commander_Keen

Crikey that kit is a bit pricey!

Yeah it is pricey. It's one good thing about this forum that you can get a bit of a reality check about stuff before buying. I've thought oxy many times but with my very low rate of use, couldn't justify it. I reckon that for me, if I can do hard brazing on small stuff with a torch I'm 90% there. The Sievert stuff I have isn't all that useful - good for silver soldering and that's all. Not strong enough for heating seized components, or breaking loctite, or bending anything, or hard brazing. So the waste of money was getting that kit instead of this one, first time around.

There's a couple of YouTube vids that put me onto it, actually made by one of this forum's members a few years back, this is the main one:

"How to bronze braze with LPG or propane gas" https://www.youtube.com/watch?v=PGwKuYP-RNo

I have a MAPP gas torch that I recently used to make some lathe dogs out of 25x5 bar; probably could have done 32x5 if I needed to. The key with these smaller torches is to do a little bit at a time. Be nice to do it in one hit but if you haven't got a larger torch...

Michael

Now that you can get size D oxy and acet from Bunnings at a pretty good price, it makes the decision between oxy and a Bullfinch a bit harder.
When I checked a couple of weeks ago Bunnings wanted a $200 refundable dep on ea cylinder and I think the gas is about $170 for both. So a fair bit of up front price but you get $400 back when you return the cylinders. If yo have to buy all the rest as well then the price starts climbing a bit but its still a lot cheaper than it would have been 20 years ago.
I quite often see torches and regs etc used at a reasonable price but that would always be a bit of a lucky dip.
I'd love to have oxy again (had it at home for around 30 years up until 2009) but I'm not doing the work I used to and so cant really justify it to myself. Having said that, when you need that concentrated heat, nothing else will do.
peter