Small brazing kits - any good?

JumbleDuck

JumbleDuck

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[Not boatie, but could be...]

I need to seal up a dozen 4mm rivet holes in a thin sheet of steel[1]. When I had access to an oxy-acetylene kit I'd have brazed them up, partly because it's easy and partly because there is less chance of heat distortion then from my ham-fisted welding.

So ... are any of the blowtorch sized brazing kits (usually MAP gas) up to this sort of work? The alternative is to take the thing to a good body shop, but they are few and far between in the wild mountain fastnesses of Galloway.

[1] The rear wing of a Citroën DS. But it could be part of a boat, honest.
 
I have a Rothberger blowtorch with hot gas (MAP) cylinder on board. recently it's been really useful brazing stainless steel and has saved me a lot of trouble. As recent examples I have made a generator spare part, and repaired the bars on the cooker. I have silver solder brazing rods and J-M flux as well as Aluminium ones. As yet I haven't used the Aluminium, but who knows. If going off to remote places I think it's definitely worth having.
 
I have a little Oxy-Propane kit, cost €60 at the local B&Q. Gets up to 3,000° and is suprisingly useful. Unlike the big kit with heavy bottles, one just chucks it in with the other tools on the offchance it is needed. Does nice silver solder or brazing.
 
DownWest said:
I have a little Oxy-Propane kit, cost €60 at the local B&Q. Gets up to 3,000° and is suprisingly useful. Unlike the big kit with heavy bottles, one just chucks it in with the other tools on the offchance it is needed. Does nice silver solder or brazing.
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That sounds promising. Works with normal fluxed brazing rods?
 
JumbleDuck said:
That sounds promising. Works with normal fluxed brazing rods?
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Yes and if you have a DS, then I would have thought there are plenty of future uses :o
For small jobs, the focused flame is good too. I brazed a new bottom on a small diesel tank, so plenty of heat available.
It is not much different to my normal Saphire torch on big bottles. Just the gas is much more expensive in disposables.
 
DownWest said:
Yes and if you have a DS, then I would have thought there are plenty of future uses :o
For small jobs, the focused flame is good too. I brazed a new bottom on a small diesel tank, so plenty of heat available.
It is not much different to my normal Saphire torch on big bottles. Just the gas is much more expensive in disposables.
Click to expand...

Many thanks. I shall look out for a B&Q. Any chance you could let me know the name of the kit you bought?

There is no problem on a DS which can't be solved with money. Lots of money. <sobs>
 
JD
It is a Castolin 2000 Flex. Our local Brico Depot is owned by Kingfisher AKA B&Q, so I expect the same kit is available in the UK. Did notice today, that it is now €69. But in general, stuff is more expensive over here. Friend bought a battery drill from B&Q on offer at £50. Same thing was over a €100 here. NIce guy, he got three sets for myself and two friends..

Loved the D19 special a mate had in Portugal. Bought it new in '72 (?) and kept in in pristine nick for the time I knew him, up to around 2002. Despite the nice weather and no salt on the roads, he did need to weld some bits after about 10 yrs.

Little story: He arrives at the Austrian border with his Spanish G/F and the guard gives him a hard time. After a bit of paper shuffling and blank looks, he demand to know what the prob is. Guard says ' You are a German , living in Portugal with a Spanish 'friend' driving a Polish car. I find that a bit odd'. Seems he had not seen a P plate as opposed to a PL plate.
 
I can't see a gas/air torch working with brazing rods. Sifbronze melts at close to 900 deg.
Some type of silver solder might just be possible
Oxy-propane or MAPP might perhaps work, but the disposable oxygen cannisters that I'm aware of cost £25 or more and last ~20 minutes, ouch!
I'd be concerned that the panel would finish up distorted from the localised heating.
Have you considered rivets, Al, iron or copper? Lightly countersink the outside of the hole and clench over into the c'sk with the pre-formed head held up on the inside with a dolly. Then dress off with a file.
 
earlybird said:
...I'd be concerned that the panel would finish up distorted from the localised heating.
Have you considered rivets, Al, iron or copper? Lightly countersink the outside of the hole and clench over into the c'sk with the pre-formed head held up on the inside with a dolly. Then dress off with a file.
Click to expand...

Why not filler or araldite? Or if it must be metal, use solder like the traditional wiped lead seams. Lower temperature - less distortion.
 
JumbleDuck said:
[Not boatie, but could be...]

I need to seal up a dozen 4mm rivet holes in a thin sheet of steel[1]. When I had access to an oxy-acetylene kit I'd have brazed them up, partly because it's easy and partly because there is less chance of heat distortion then from my ham-fisted welding.

So ... are any of the blowtorch sized brazing kits (usually MAP gas) up to this sort of work? The alternative is to take the thing to a good body shop, but they are few and far between in the wild mountain fastnesses of Galloway.

[1] The rear wing of a Citroën DS. But it could be part of a boat, honest.
Click to expand...

My Rothenberger MAPP torch gets hot, i haven't used it for brazing, but i think it would do it. Back in the day we used to use Oxy/Acetylene for automotive brazing (new wings etc), heat distortion was always an issue. Replacing wheel arches could easily distort a whole rear quarter if you wasn't careful. For the job you describe i would not braze, MIG would be vastly superior, or solder them with a MAPP torch.
 
solent clown said:
are you painting it yourself or getting a bodyshop to do it?
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Bodyshop.

I need to check that it fits OK - if it does fit, or can be made to fit, I'll fill the holes, get it soda blasted and primed and then hand it over for painting. No one-stop shops here, because everyone and everything is so spread out. The nearest soda blaster is the best part of a hundred miles away.

Edit: For those who don't know, the rear wings on a DS are easily removable, as you have to take them off to remove the rear wheels. They are held on by two pins at the front and one bolt at the back. Painting off the car is therefore easy. In fact, with the exception of the roof, every single bit of visible bodywork can be removed for painting.

rear-wings-59-c[ekm]300x227[ekm].jpg
 
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If the bodyshop wont do the holes, I would recommend (if you are not expert, if you are then please ignore me) you epoxy some small flat plates behind the holes then simply fill them. Do it well before it is to be painted.
That way you will not be risking any distortion. If you do not know how to use lead, don't try, it isn't a quick and easy skill to pick up.
 
solent clown said:
If you do not know how to use lead, don't try, it isn't a quick and easy skill to pick up.
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I used to take bodywork to an excellent nearby chap who could lead load like a dream. Unfortunately he has now almost retired (he's well into his eighties) and his work is not what it was.

Epoxy is an interesting idea, but I'd rather have metal of some sort there.
 
solent clown said:
If the bodyshop wont do the holes, I would recommend (if you are not expert, if you are then please ignore me) you epoxy some small flat plates behind the holes then simply fill them. Do it well before it is to be painted.
That way you will not be risking any distortion. If you do not know how to use lead, don't try, it isn't a quick and easy skill to pick up.
Click to expand...
Halfords sell an aluminium mesh which is excellent for providing a substrate into which chemical metal can be bedded behind even quite large panel holes. We recently used it on some holes 75mm diameter in some electrical panel doors which after rubbing and priming were completely blended in yet the whole patch was less than 3 mm thick, with inner surface also reasonably fair.
 
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