Ideas on how to repair a cast iron T slot

[not done it yetParticipant @notdoneityet]

I have a broken T slot which needs repairing. Question is: What would be the best way?

My first thought is to mill the bottom to remove the sideways slot and back to make space for a bolt hole through the casting. Then mill backwards (up on this pic) at an angle. A shaped steel "bolt", to replace the parts lost and removed, would be fitted through the hole and secured underneath and either welded or brazed to the cast.

The idea is that steel would give strength on the corner of the two slots and support the cast on the angled join. The intention is for a working repair, not just a 'decorative' one.

I'm open to suggestions as the casting is likely around 100 years old and is not replaceable. There are another couple of angles in an album.

Slots are 1/2" and their base width is 1"

[not done it yetParticipant @notdoneityet]

[Howard LewisParticipant @howardlewis46836]

Any chance that you could manufacture a short length in steel, cut out the cast iron, entirely for a few inches and retain the steel repair with countersunk screws?

Howard

[I.M. OUTAHEREParticipant @i-m-outahere]

How thick is the material in the base of the t slot ?

What is the slot between the two sections for ?

[Brian Sweeting 2Participant @briansweeting2]

post deleted by me

Edited By Brian Ess on 03/08/2017 16:55:22

Edited By Brian Ess on 03/08/2017 16:55:56

[not done it yetParticipant @notdoneityet]

TEST

[Neil WyattModerator @neilwyatt]

If it is worth the investment, get an expert in cast iron repairs to build it up using suitable sticks (it can be done) and re-machine.

Neil

[Dave HalfordParticipant @davehalford22513]

Suitable sticks meaning pure nickel. All you need is 90A and 2.5mm rods very easy welding.

However there a lots out there with a percentage of FE in them. Use one of these and you get un machineable scrap metal that you can only angle grind very slowly.

Dont ask how i know.

[MuzzerParticipant @muzzer]

Jodie on weldingtipsandtricks.com recommends aloominum bronze fillers for cast iron (rather than the more common silicon bronze). Seems to work for him but clearly it will be expensive and time consuming no matter what you do. Is it really worth the candle or is this the justification for buying something better – and keeping the old one too of course!

SIF seem to stock various aluminium bronze rods (10% aluminium, 90% copper etc) at about £90 for 1kg delivered. Can't say I've any experience myself – my rods are the silicon bronze (3% silicon, 1% manganese, 96% copper) "Sifsilcopper 968" product that I have used very successfully for TIG brazing steel.

Murray

[BazyleParticipant @bazyle]

Rather odd arrangement of T slots. Did you find any clue as to the maker? I've never seen the like before. It could be the only one left so worth taking a bit of care over the repair, and let 'Lathes' have some pictures.
It also looks like there is an intermediate plate missing or this base is from a different model.

[not done it yetParticipant @notdoneityet]

Having trouble repying, fellas.

[Anonymous]

Posted by Bazyle on 04/08/2017 16:44:10:

Rather odd arrangement of T slots. Did you find any clue as to the maker? I've never seen the like before.

I don't think it's a machine tool, looks more like a box cube or tilting table.

Andrew

[IanTParticipant @iant]

It's the work table on an Alexander Shaper…see:

http://www.lathes.co.uk/alexander-shaper/

(and no I'm not the Mystic Meg of shaperland – I had a chat with NDIY a week or so ago)

Regards,

IanT

[BazyleParticipant @bazyle]

"With only a single example known"

and then there were two!

Perhaps the lack of name cast on the ram and tool slide mean this one was the prototype.

[Neil WyattModerator @neilwyatt]

A very strange machine! Hardly any daylight under the tool, and the vertical face where you would normally attach and angle bracket is beyond the reach of the ram.

But hang on… perhaps you could move the shaper head and attach it to the central t-slot? Or fit it on a raising block.

[not done it yetParticipant @notdoneityet]

If this posts it means that I cannot post by simple 'copy and paste'

Nowt to do with browser cache, but maybe something to try to prevent spammers?

I make copies to the clipboard because posts disappear so easily (keyed in a reply to Howard and XD about 5 times now over a couple of days)

Yes, it is part of a completely manumatic Alexander. I bought it to try out a cheap shaper, not knowing what it was, while looking for a Drummond.

[Mark RandParticipant @markrand96270]

While the position of the break is at a very vulnerable spot, it's also a very good location for a weld repair, since the likelihood of distortion is reduced by the exposed location.

Pre-heat the part to about 350-400°C and use 98% Ni rods with a stick welder to build up enough metal to mill or shape the T-slots back to where they had been.

Don't be afraid to add far more metal than was needed for a minimum buildup. It's simple to cut it off again and you will get some undercut/erosion of the original metal unless you are experienced with the process.

The High Nickel rods will have a slightly different colour to the original steel (more yellow), but because they don't absorb carbon. They will not be hard to machine.

As a datum, this is how I repaired some gears on my shaper and found that the weld machined very easily.

[IanTParticipant @iant]

Interesting info Mark.

I had a cracked (standalone) Myford countershaft many years ago that I took into college for the 'welding' instructor to look at. He repaired it but there was some really bad language flying about at the time. The finished job did look like a SIF braze but he didn't (or couldn't) pre-heat it – so that may have been causing him some problems.

Anyway, it's now been given to a friends son (together with an ML4) and it's still solid after all these years…

Regards,

IanT

[Ady1Participant @ady1]

I'm currently slowly building up the bottom of a cast iron milling slide with standard rods and a cheap inverter, my current pet project to simplify and beef up milling on my lathe

Will let you know how I get on, early days yet though

First impressions are good if the cast lron is good quality close grained type and any oil is completely removed filed or ground off before welding

[not done it yetParticipant @notdoneityet]

Thanks for the suggestions. I am going to take it to my local fabrication welder fellow, to see if he can weld it up as I am not expert enough to weld cast iron on a one-off such as this.

[Ady1Participant @ady1]

A zero experience noob effort

Each bead needs thoroughly cleaning and preparing (i used a rotary wire brush) and a hand held angle grinder squares it off

How successful a job you get will depend entirely how much skill and care is put into your wee job

[vintagengineerParticipant @vintagengineer]

I have repaired similar. Machine the top of the tee off for a long enough to get four threaded holes in. Then bolt a cast iron plate in the machined place. Countersink the holes in the plate and make four studs with countersunk heads.

Fit the plate with these then machine the studs flush.

[Trevor Drabble 1Participant @trevordrabble1]

NDIY , For cost of postage , I have some CI rods and flux available I have used with oxy-acetylene for use by your welder if reguired .

[not done it yetParticipant @notdoneityet]

Hi Trevor,

Thanks for the offer. I will be replying by PM as soon as I catch my fabrication man in his workshop – he is mostly out on jobs as he is generally in demand.

[Author]

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