tapping cast iron
 

MegaSack DRAW - This year's winner is user - rgwb
We will be in touch

[Closed] tapping cast iron

13 Posts
8 Users
0 Reactions
92 Views
Posts: 41395
Free Member
Topic starter
 

I broke a cast iron grate off my new hob last night (it was bent and I was trying to straighten it).

The only way I can think of repairing it is to bolt it back together which would require tapping into it. It looks like cast iron. Is this a go-er?

I'll look into a new one but given the hob retention kit was £25 I am guessing it may not represent "good value" (And I would not recommend a ex-dem hob from Ikea!)


 
Posted : 24/08/2009 8:21 am
Posts: 17
Free Member
 

Suspect it'll take some doing, it's a very hard substance normally. I'm fairly amazed it was bent - normally cast iron just shatters, thats kind of an integral part of cast iron.


 
Posted : 24/08/2009 8:24 am
 Smee
Posts: 0
Free Member
 

Should be easy enough to do, it cuts pretty easily. Shouldn't need any cutting paste either as cast iron is self lubricating apparently


 
Posted : 24/08/2009 8:28 am
Posts: 0
Free Member
 

Al - I have a set of taps and dies if you want to borrow them - but I tend to agree with coffeeking - cast iron will be difficult to drill and tap


 
Posted : 24/08/2009 8:28 am
Posts: 0
Free Member
 

I'd say it depends on the cast iron. The stuff is relatively soft and easy to machine and tap, though a bit messy as you normally get grey dust everywhere. The problem is that if it looks like it's come straight out of a casting mold, rather than been prevously machined, like a I guess a grate would be, then it's a bit like an armadillo, soft on the inside and crunchy on the outside. Once you get though the skin it will be fine, both to drill and tap, but you may have issues with the tough outer skin.


 
Posted : 24/08/2009 8:35 am
Posts: 0
Free Member
 

If its 'new', can you not try it on with a warranty claim. Just say it broke off under normal usage and let the warranty company try to prove otherwise ?


 
Posted : 24/08/2009 8:35 am
Posts: 41395
Free Member
Topic starter
 

Cheers. I think it's a tricky one as I'd have to drill in at a couple of odd angles, keep alignment correct, then tap.

Is there another way of doing it? Superglue didn't work *opps: and I can't think of anything that might be heat resistant enough.

NFE I may try that but the hob was sold "as seen" meaning I am probably screwed. It won't look good to say "it was bent when I got it, honest, it broke when I was trying to straighten it"!


 
Posted : 24/08/2009 8:41 am
 Smee
Posts: 0
Free Member
 

Try Brazing it together.


 
Posted : 24/08/2009 8:47 am
Posts: 17
Free Member
 

An experienced welder with a furnace might give it a go, but it'll cost more than it's worth I suspect - you can weld cast but it needs heat treating and welding in a special way and even then tends to become more likely to break/crack etc in future. Brazing - not sure, depends on your heat and location obviously. If it's bent though you need it straightening first...?


 
Posted : 24/08/2009 8:50 am
 wors
Posts: 3796
Full Member
 

piece of piss, as said cast iron is easy to machine, unless of course it has been chilled.


 
Posted : 24/08/2009 8:51 am
Posts: 17
Free Member
 

Depends on the type of cast iron wors


 
Posted : 24/08/2009 8:53 am
 wors
Posts: 3796
Full Member
 

Depends on the type of cast iron wors

okay assuming it is SG Iron


 
Posted : 24/08/2009 8:56 am
Posts: 0
Free Member
 

Take it to your local Blacksmith, yes, they still exist!

he may be able to fix or use it as a pattern to cast a new one


 
Posted : 24/08/2009 9:04 am
Posts: 41395
Free Member
Topic starter
 

coffeeking - Member

If it's bent though you need it straightening first...?


Indeed - though there's a way round it. I'll call the spares folk and see how much they want for a new one. I think I've got a reasonable argument with ikea as the guy just boxed it up without allowing me to inspect it properly.


 
Posted : 24/08/2009 9:13 am