i want to join an ally tube to an ally casting(inlet stub to manifold),
i was thinking of using some ally weld stuff that i got at a show,then i discovered an empty tube of jb weld,question is,is that strong enough or should i weld it?

i'd guess an empty tube won't be strong enough. One with some stuff in is supposed to be - although you'll have issues with doing a tube as you'd got to get bits hot / keep them hot etc whilst doing the piece.

i had planed on putting the manifold on the gas cooker to heat it and keep it warm for the welding,jb seemed a lot less hassle

I bought Alumiweld from Stoneleigh at the car restoration stand. The guy was really helpful and 1/2 the price of the self confessed "Foreigner" selling a similar product. Id use that. I triedit on a peice of 1/4" ali plate and it works a treat. Need a small flame though as a big lamp just cooks the whole lot. It might crack the casting as well if you dont heat it in the oven first.

cant find anyone selling alumiweld over this side of the pond,got any contact details?

Frosts sell it under a different name

Here's a link to Welduk's offering :-

Aluweld linky

make sure you have a stainless steel wire brush, its essential that you remove the oxidisation prior to joining the metals, done correctly you get a really strong joint cant comment on whether it would be strong enough fro making a manifold as you have both weigh and the vibrations of the carb. I have used the Weld UK stuff and had good results all be it on lighter gauge stuff

JB weld is great stuff but how you contruct the joint wil be the important thing. If the two bits are just butted up together & a load of the stuff plastered around the join then I dont think it'll do but if you make it so the tube is actually pushed into the casting & the two parts have JB coating both mating surfaces before it's assembled & it's well worked in to fill any gaps then it may well work OK.
If you can get hold of the slow setting stuff it's stronger & withstands higher temperatures.
I JB welded 5th gear back onto the mainshaft of a Skoda pickup when the splines were stripped a couple a years ago, it was still going when I last saw it before it was sold best part of a year later.

John, I have some Lumiweld, which is the first generation stuff. Your welcome to a stick, (and the loan of the S/S wire brush), if you can wait for the next Newlands. Cheers Ray PS U2U me if you can wait, :-)

cheers for your replies peeps,ill order some loonyweld i think,ive got about 12" left over from the bit i bought 2 years ago,see how that goes

I see that there's a 'new generation' of these rods called HTS-2000. That look like they may be easier to use as you don't seem to have to scratch through the oxide layer - anybody tried these?