DuraFix aluminium brazing rods.

[DaBit]

I wonder if anyone here ever used Durafix aluminium brazing rods? They sound like just what I need for constructing frames etc. from stock aluminium bars/profiles/sheet. Currently I use polyurethane glue or those 'crimping nails' (don't know the English word) to join separate parts.

link:
http://durafix.com/brochure/p1.htm

(next page link is very small on the right bottom)

[Peter_1]

www.novatio.nl or www.novatio.be has almost the same product.

We use it to repair small evaporators. You can't fill gaps of more then 1 mm. Once it melts, it is like water

[DaBit]

Fairly easy to work with?

I intend to use that stuff as a replacement for glue and nails.

As far as I can see the rods contain ~94% Al and ~6% Zn. This mixture gives an eutectic point at 385 °C, which seems close to the melting point of that stuff.

I think I will try that stuff. It's not very expensive.

[Peter_1]

Almost same as soldering with electronics solder.
Heating the surface and as soon surface is heat enough, remove flame and add solder without flame.

Glueing is not that bad. An Airbus is almost completely glued.

[chemi-cool]

hi DaBit,

I have been welding aluminium for many years.

there are many kinds of aluminium and its important to match the electrode to the material youare going to weld.

the best is argon welding machine- very expensive.

with oxy/ acytilene with excesive acytilene. one important tip, aluminium not like steel, does not change its colour when melting but just before melting, it shines.
do not use dark welding goggles, sunglasses will do, clean the erea to you are going to solder with alcohol, heat the base metal first, remember that heat travel real quick in aluminium so be cerful not to burn yourself.
afret you heat the base metal, melt a drop from your rod and wit the torch, slowly spread it and repeat if nececary.
do not over heat as the whole thing will melt.

I always use Castoline - suiss made.

do some experiments till you get it right.

any questions?
I'm here to help.

chemi

[DaBit]

Originally posted by Peter_1
Almost same as soldering with electronics solder.
Heating the surface and as soon surface is heat enough, remove flame and add solder without flame.

Sounds easy and quick enough.

Glueing is not that bad. An Airbus is almost completely glued.

I know, but they use a good primer, special glue, and probably an autoclave for hardening out the glue. I am using no primer and standard 2-component polyurethane glue (Bison Kombi Power). It works, but it is slow since the glue has to harden out. You also have to keep on clamping until the glue is hard enough. The bond is strong though, if you clean the bonding surfaces well.

Originally posted by chemi-cool
[B]hi DaBit,
there are many kinds of aluminium and its important to match the electrode to the material youare going to weld.

I am using standard aluminium sheet and profiles from the DIY stores (would be Home Depot in the US I suppose). No idea what kind of aluminium that is.

the best is argon welding machine- very expensive.

Purchasing a TIG welding machine for the few times a year I want to join aluminium is out of the question, even a second hand machine.

In most cases a very strong bond is not even required. Samples of things I would like to weld instead of glue:


(support bracket for CD-ROM players etc. in my custom computer case)


(airtight mainboard housing to prevent condensation due to low CPU temperatures)

For these things I don't need a perfect strong weld. Glueing also works fine, but as mentioned before, it is slow and it requires clamping.

That's why I like the idea behind these rods. They can be used without a special protective argon (or helium) atmosphere, they melt before the base material melts, and they can even be used with a normal propane torch according to the manufacturer. This would mean that they should work with my oxy/fuel (fuel is a special mixture which looks a bit like MAPP) torch too. Especially when using a carburizing flame to reduce oxide buildup.

[chemi-cool]

piece of cake,
have a go on some left overs. you have to heat the base metal before! its important.
oxy/fuel should do. try to get a narrow flame and spead the drops from the rod with the flame.
are the rods caoted? or you have the flux separate. if so, make sure it says on the box "for aluminium"

chemi

[Karl Hofmann]

I've not used durafix, but have used both Lumiweld and Braze Perfect. Both of these products are brazing systems as opposed to welding and need only to be heated with either a plumbers torch or better still a MAPP gas torch.

Lumiweld sounds very similar to your Durafix, it is the choice of many a classic car or bike restorer and relys on the use of a stainless steel wire brush to clean the sections to be joined, heat is applied to the work pieces and then the filler rod is applied with the heat off the work. when the required amount of filler is on the work, heat is then re applied and a stainless steel rod is then used to scratch through the molten filler to the alloy below. The low melting point of the filler rod makes this all very easy.

Braze perfect uses a stainless wire brush to clean initialy, but then a flux must be applied before assembling the work. The filler wire is applied with heat on as this product has a much higher melting point, several times I have been caught out when I have been distracted and the work piece has melted. Both of these systems work well with thin section alloy. I use them for brazing in repair sections on automotive air con tubing, although I now also use the crimping system from Vulkan Lokring

[DaBit]

I ordered a 1-pound package of that DuraFix stuff. Let's see how it works out.

The procedure sounds indeed very similar to Lumiweld's

[chemi-cool]

DaBit,

just remembered, there is another welding material for low temperaturs which I use to solder aluminium tubes to copper on domestic freezers.

if it interests you, I can get you the details.

chemi

[Peter_1]

I'm interested too Chemi

[chemi-cool]

okay peter,

give me sometime to find out all the details and I will let you know.

chemi

[DaBit]

Originally posted by chemi-cool
DaBit,

if it interests you, I can get you the details.

chemi

I am very interested. That would solve a lot of problems if copper-alu connections were easy to make.

[chemi-cool]

hi peter and DaBit,

on the rods box there is nothing.

I'm trying to locate the importer.

chemi

[chemi-cool]

hi DaBit,

un fortunatly the agent here told me that they dont make them any more. enviroment problems he said.

but if you choose from a catalog, a wide range low temp aluminium rod and use a lot of flux, it will solder easy copper to aluminium.

alays in this procedure, expand the copper tube and insert the alum. tube inside vartically.

I will make an exampel and post a picture.

what you can do to get wiser is check with castolin, magna and more of maitenance electrode manufacturers.

chemi

[chemi-cool]

I think I've found it at http://www.breckocorp.com/gbsazm.htm

please check it.

chemi