Welding cast iron? Calling metalurgists

I want to bolt Mk3 type 280mm brake carriers to my Mk1 hubs
I presume the carriers are cast?
Looks as though I can achieve this if I weld up the existing carrier mounting holes, weld a little around the lugs of the existing to extend the shoulder that the bolt head rests on, then redrill the holes a little closer towards each other.

I'm not worried about the strength of the carriers where I am going to redrill but will plugging the existing holes and building up the shoulder with the MIG affect the strength of the casting in some way?

Any metalurgists out there to help me?

And what was the cause of brake failure on the Reeves Mk1?.......

 

Comments anyone?

 

email this guy info@andypullingengineering.com

its me dad, he will know!

 

I've never really heard of anyone successfully welding cast. Don't think mig is any good at all.

 

I've seen the lads at work using a stick welder to weld cast iron. I think the welding rods are specially for cast too

 

you can weld cast, its a pig tho and cracks iirc

 

Not sure if there is a mig wire available for welding cast, but you can deffo get rods for MMA (arc) welders for cast metals, but you'll have to know exactly which type of cast it is as there are loads of different types. You used to have to preheat the area before welding years ago, but not sure now with the new rods on the market. Personally I wouldn't attempt it.

 

ive played around with a tig attempting to weld various things and cast iron is nearly impossible. pre heating helps and eventually it sticks together although i wouldnt trust it. now cast steel [if there is such a thing] was easier and i found it easier to build up the thickness.

 

Blacksmiths weld cast iron by heating the whole thing red hot in the forge before welding. Otherwise it cracks - I've seen it done on exhaust manifolds, but if you do it on brakes you should invest in some life insurance.

 

When did the brakes fail on the reeves mk1?

Why do you want to go to all this trouble to fit 280mm brakes when theres much easier ways to do it?

 

What are the easier ways then please?
I'll appreciate your thoughts.
It seemed pretty easy to me to just drill the mounting holes on the carrier 10mm closer together?

 

isnt there someone/some place that sells adapters to allow 280s to be used with normal mk1 callipers? think they are lik 50 iirc

 

TSR used to, so there must be somewhere else that does.

 

would you trust your brakes with with welded cast iron?

 

Im a welder and theres no way id try and weld cast esp on brakes.

Theres no real way to know if youve penetrated 100% without expensive test equipment.

Use some adapters to space out your original caliper or use adapters that use the 280mm carriers and the original mk1 hub.

These use your original mk1 calipers with 280mm discs.

http://cgi.ebay.co.uk/run-g60-brake...oryZ9889QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

HTH.

 

LOL, ive seen your weld drop off before its even cooled down, and no it was not overhead welding, and also how you get it to look like a bubble bath every now and then .

 

you need to pre-heat the metal first otherwise it will crack due to thermal shock, like others have said, theres no way you can tell if you've penetrated without dye-pen or something similar.

 

if you still want to go the welding route(not my choice)go to flavels in thornaby and see what they say,if anybody can weld them then there the guys

 

Its likely to be cast steel, not cast iron so should mig ok.
If it is cast iron then the only way to do it is with cast rods and a stick welder. As long as you dont put too much heat into it it shouldnt crack. Can pack the caliper in lime to slow down the cooling, but never bothered with it myself and havent had any problems (so far!)

Iirc, if you get a grinder onto caSt iron, the sparks tend to "stick to the wheel" rather than fly off like they do on steel.