Repairing diecast, aluminium, pot metal and cast iron

[tazmantic]

Yeah, I have seen this stuff but not sure if it's available in the UK but you can get Durafix. I think it might be similar.

[pennymachines]

It's very similar to the zinc alloy HTS-2000 I've been experimenting with (topic merged above).

It claims a slightly lower working temperature of 350º versus HTS-2000's 380°C - 408°C, which could be helpful.
Unlike my rods, it comes with a pot of flux. This offers several advantages. The flux "turns from powder to liquid at the exact moment when the rod should be applied" helping you to judge temperature - particularly important on aluminium which doesn't glow red before melting. It prevents re-oxidation of the aluminium during the braze (obviating the fiddly wire brushing of the molten join), and it helps the molten rod flow.

Price-wise however, it doesn't compare favourably in the UK.
5 x 24cm HTS-2000 rods for £12 (from ebay or http://www.aluminiumrods.co.uk/)
5 x 18" Muggy Weld rods plus flux for £66.10 (from Caswell).

[gameswat]

These rods work great because it's so important to keep the pot metal as cool as possible to stop it cracking or exploding. As for price, no other product has worked for me, so not an issue. Previously I would either glue, and/or bolt together the breaks. I was so happy with these rods I eventually tried all the other products made by Muggy Weld and have had great success with them all. Have used a hell of a lot of their Silver Solder to restore small cast iron breaks and stainless steel repairs. But PM, I do also use a different brand of rod for alloy welding.

[pennymachines]

Agreed - if it does the job, it's well worth it.

[gameswat]

I just looked into the other alloy rods I've been using for the last 3 years and they're actually HTS 2000. They seem to work very well.

Yeah have seen this stuff but not sure if its available in the uk but you can get durafix think it might be similar

No agent in Aust either, I just buy online from the states.

[tazmantic]

Bought some HTS2000 rods off evil bay, well think they are as listing has now been changed lol and have been having a try to see what happens, managed to weld 2 bits of ally no problem and the weld was really strong gave it the hammer test and the ally just bent and weld stayed intact
So thought I'd have a go on some scraps of pot metal well ain't that a different story as said the pot metal and rods melt at about the same temp so before you know it these a big blob lol. It says in the instructions with pot metal to actually melt the rod with the flame then heat it all and try to like mix it together with a piece of steel I sort of had some success but its tricky as think my blow torch flame is too big really need a fine flame.
I did successfully fix a lever off an air rifle, the boss was quite hefty so didn't melt quickly but lever did so I made a new lever out of ally and welded it on to the pot metal boss worked a treat

[treefrog]

Digging up old topic, I was interested whether anyone had attempted to have a go on a precious part other than Gameswat great resto of that figure. Especially what the original poster mentioned and a common issue in our world, cracked rather than broken castings.

The Muggy Weld product sounded excellent with the use of flux and lower temperature, but I could find no supplier in the U.K., they use to sell on Amazon Uk, but saw this on their website

Contains cadmium. Super Alloy 1 cannot be imported to countries in the EU due to import regulations

, maybe that will change in 3 days time, but I doubt.

They have great advice sheet though on how to use and mention that a crack needs to be thoroughly prepared and rubbed down inside, which means making the crack larger to get a file in. Also the products are not suitable for cast aluminium, except

For castings thicker than 1/8″ we recommend beveling the base metal with a grinder prior to soldering

https://www.muggyweld.com/wp-content/up ... ctions.pdf

Before I destroy a poinsettia casting, thought I would check any results

[gameswat]

Tree, the Super Alloy 1 isn't what you want for this job I think. Fine if you are painting or plating the repair, but the colour of the product will not match cast aluminium when polished or burnished, it darkens the way pot metal does. You'd need to either use the Muggy Weld 5 alloy rods. But those need much higher temperature, a little lower than the cast aluminium melting point. I've done it but you need an oxy torch to get enough heat to something the size of a slot casting. And with that much heat you 'll often cause some kind of warping with such old castings. Alloy Tig welding would likely be a much safer option, but I'm not sure how that colour matches to old cast alloy?

[gameswat]

Tree, the HTS2000 rods are good for repairing aluminium damage and making things, but again a terrible match colour wise for cast alloy. I would never try and use these on the exterior of any castings that are to be left raw. I recently had to fill some drill holes in an almost 100 year old cast alloy panel and chose to make my own plugs from old castings to fill the voids. I slightly chamfered the holes both sides and then gently rivetted the plugs into place, then ground back the detail with a die grinder. Effect is pretty much invisible. And no heat placed in the middle of delicate castings which would definitely have caused warping and possibly cracking.

[treefrog]

Thanks GM, it has answered the question as around delicate castings as this would probably have been my main concern given how thin some are and of course colour matching.

I guess the alloy 1 would be good for pot metal parts, not that we can get here