Repairing broken cast iron grate

[News]

Recently bought a new 14 inch fireplace grate, and, on arrival, it was broken. One corner, complete with leg, snapped off. The supplier is sending a replacement, and does not appear to want the damaged item returned. I'll keep the damaged one as, at a pinch, I think it would probably work as it balances well on three legs and, as the damaged corner is at the rear, could probably be wedged in place.

Could I repair the damage? I believe welding cast iron is not straightforward, and I can't weld anyway, but any other method? Is there a glue for that range of temperature? I cannot imagine fire cement working?

[Bill Wright]

Ignorant of the fact that it can't be done I welded a cast iron vice many years ago, and I've been using it ever since.

Bill

[F Murtz]

Welding cast iron is usually not that difficult depending on type and strength required,it can also be bronze brazed.

[harry]

There are two ways. One is to braze it using gas welding.

The other involves special arc welding rods but the job has to be preheated with gas to prevent expansion cracks.

I once tried to electric weld wrought iron. That was a failure.

[Brian-Gaff]

It very much depends on thw qualityof the casting from what i can remember from my childhood. Some are very porous and tend to crumble when welded. Bit like welding powder!

I guess if you were careful and had the right materials it could be drilled tapped and screwed together, though when heatcycled it might crack due to the expansion and contraction of the different metals.

Brian

[Huge]

I've had 3 goes at welding cast iron, one very successful (a grate, as it happens!) and two miserable failures (a frying pan and a bracket from an old bed.)

I believe you need special rods, which I wasn't using, which probably accounts for the failure.

[F Murtz]

Yes and differing ones depending if you want strength or beauty and also expensive.

[News]

In message , F Murtz writes

The original point was, welding is not an option :-)

Any suggestions that don't involving arc welding, brazing or any other form of welding?

[Huge]

But less so than buying a new {whateveritis}

[Huge]

Drill holes & bolt/rivet some kind of brace across the break?

Use this as an excuse to buy an arc welder?

[News]

Yes, I think that is the best idea.

I'm already inventing excuses to buy an electric chain saw, having chatted to a neighbour who was doing in a few seconds what takes me a lot longer with a hand saw!

[damduck-egg]

Depending on where the ashpan needs clearance put a bolt through the slats of the grate ,put some oversize washers each side and a nut tight enough to hold in place ,hacksaw the bolt to length and you have a replacement leg . If such an arrangement gets in the way of the ashpan it might be possible to use some studding and bend into a shape that clears.

G.Harman

[Bill Wright]

If you get one, watch a few of the safety vids on Youtube.

Bill

[News]

In message , [e-mail] writes

Yes, that is roughly the conclusion I had reached but, given that the slats are already there, I think I'll be able to use them to bolt the two parts together using penny washers, and thereby use the original leg. Once in place, the grate tends not to move often. Thanks.

[News]

Thanks Bill. I have always shied away from chainsaws, thinking in terms of petrol, but, having seen a neighbour effortlessly cutting up a sycamore tree with a mains powered Makita, may think again. My needs are simple - logs up to 3 or 4 inches, old pallets etc so a cheap one may suffice.

[news]

Chances are the vice was cast steel.

I welded cast iron with nickel rods successfully but they cost a lot.

The alternative is to heat the casting to nigh on red heat so it's in its plastic region, weld and then slowly cool it otherwise it tends to fail immediately adjacent to the weld.

For blocks and gearboxes metal stitching is more successful but not worth it for something cheap like a grate.

AJH

[Tim Watts]

How about a battery one if it's for odd small work?

I've been *very* impressed with my Bosch LiIon mower and hedge trimmer.

[Tim Lamb]

In message , News writes

Any chance of drilling and tapping. Cast iron is easy to drill and cut a thread. Clearance hole from top and tapping size down the leg. 6mm cap head should hold it together.

I would attempt welding as I have some rods intended for cast iron jobs. Not had any problems with local cracking on cooling where the total thermal mass is low. Anyway, you don't weld:-)

[John Rumm]

You can do a silicon bronze braised repair on cast iron. You might be able to get it hot enough with a mapp gas torch and some good padding round it to keep the heat in.

[newshound]

I'd expect to be able to do it with the big burner (25 mm) on my propane cylinder, with judicious insulation. Any rod suitable for steel should be OK (I would have thought). Easy-Flo flux.