repairing machine table

[alan knightParticipant @alanknight67321]

Hi all, previous owner of my small milling machine had managed to machine a few digs into the table. (which is beyond me how they managed that as Im a religious believe in packing work off the bed). Anyway I would like to repair these bits as they drive me nuts. I was wondering if it was possable to fill any defect with silver solder and then file and polish it level with the rest of the bed. If so what would be the best grade. I dont really want to go down the road of miging the bed up as having to start grinding a super hard weld crust off a bed which trammed to withing a thou doesent sit well with me.

Regards

Alan

[alan knightParticipant @alanknight67321]

[JasonBModerator @jasonb]

I doubt you will be able to get sufficient heat into the table to silver solder with most heat sources, brazing with oxy-ace may do it but you would want to pre heat the whole thing.

I'd leave it alone.

[wheeltapperParticipant @wheeltapper]

Hi

I drilled a hole in my new mill table.

what I did was to mix some cast iron dust with araldite and fill the hole.

rubbed it down when it was hard and it hardly shows now.

use the regular araldite not the quick setting stuff.

Roy

[KWILParticipant @kwil]

As Jason says you would have to heat the whole item first . Silver solder is not the best thing, a "proper" welder would use a high nickel electrode.I have seen an example of such use, but why bother.?

Edited By KWIL on 25/02/2012 14:13:26

[David LittlewoodParticipant @davidlittlewood51847]

Alan,

I suspect you would risk distorting the table if you heat it locally. Personally I would not bother – as long as the dings are small, and you carefully stone off the inevitable raised bits around the edges, there will be no detriment to the function. If you really can't live with it, I'd go with Wheeltapper's suggestion.

David

Edited By David Littlewood on 25/02/2012 14:40:52

[_Paul_Participant @_paul_]

Your'e talking about using a lot of heat on a nicely seasoned/machined/scraped and probably well bedded in piece of tooling what do you think a probably quite localised patch of high heat will do to it?

The Araldite and cast iron dust method does work my old Taylor mill is testament to that and you can buy proprietry compunds which do the same thing but better.

Plugging with similar material works well on round holes.

If you are determined to do something serious with it why not have it ground on a surface grinder if there is enough meat to grind out your marks, again though removing metal may have unwanted distortion effects.

My 2 pennorth

Paul

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

Hi Alan ,

On no account heat your table up to weld or silver solder – you would wreck it and the total regrind that would be nescessary to repair would be difficult and expensive .

For round holes make cast iron dowels and press or bond them in . When firm carefully dress them back to table surface .

For significant digs and slots clean them up to some simple clean shape and make a shaped piece of cast iron to fit . If it is a self holding shape bond it in . If not self holding then bond in and back up with specially made cast iron pins or screws . Design screws as countersink head such that any slot gets cut away during dressing process just leaving a bit of the cone .

Wheeltappers iron dust in Araldite is good for filling smaller holes and odd scrapes . Ready made compounds are available for this purpose .

Dressing back is a precision operation . In the absence of surface grinder file down to about ten thou proud using a shim filing guard and then use scraper and surface plate to finish dead flush .

In an older style large workshop you would always find things that had been 'pegged' to repair damage or sometimes just to fill casting flaws in new work . Lots of high quality rotary tables have pegs in them – usually so well done that you would have to look very hard to find them .

MikeW

[alan knightParticipant @alanknight67321]

Thanks for your input lads saved me from wrecking a valueable tool. I will have a go over her and see what i can fix with epoxy is there any reccomended brands for a better result?

[JasonBModerator @jasonb]

JB Weld is good and "chemical metal"  by the people who do plastic padding is a bit thicker, There is probably something in the Devcon range as well.

 

J

Edited By JasonB on 25/02/2012 16:56:59

[Peter G. ShawParticipant @peterg-shaw75338]

Can I ask a simple question?

Is it still possible to get regular, ie long curing time, Araldite? I see plenty of Rapid and other variations on a theme, but the standard 24 hour stuff appears to have disappeared.

Regards,

Peter G. Shaw

ps. I know Araldite is a trade name, and that there are other epoxy resins available, but I have been using Araldite standard since about 1965 – until it ran out, that is. But I find that when all else fails, even Araldite Rapid seems to be willing to try and do the job, whatever it is. And so, I would like to stay with Araldite.

[wheeltapperParticipant @wheeltapper]

I got some regular araldite in Buy and Queue. I won't use the rapid stuff, it doesn't get as hard.

Roy.

[Keith LongParticipant @keithlong89920]

Roy

Don't be too dismissive of the rapid version, I've found that the very fact that it doesn't set as hard as the slow version makes it MORE resistant to fracture under shock loads – can be a useful property at times.

Keith

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Alan, I have to agree with all that has been said about silver soldering or welding your milling table. Even if you could get enough preheat into it to start with, it's unlikely you will be able to control the distortion of the welding process. The filling idea's are a much safer way.

Regards Nick.

[Ian S CParticipant @iansc]

I filled a hole I put in my mill with some stuff I found at the local dump years ago, its a small tin of dark grey powder that mixes with water, can't remember what its called but it said something about filling hols in castings at foundries, so I gave it a go. Looking at it today, apart from the fact that it is shinier than the rest of the table, it looks good after 10yrs or so. Ian S C

[Sub MandrelParticipant @submandrel]

I understand JB weld knocks spots off chemical metal. Can't wait to try it.

Neil

[JasonBModerator @jasonb]

The only thing to watch with JB weld is that its quite a bit runnier so will slump on anything but a horizontal surface, also takes a lot longer to set.

 

Oh and make sure you get the right one, red & black tubes are what you want.

 

J

Edited By JasonB on 26/02/2012 20:28:24

[_Paul_Participant @_paul_]

In our local motor factors some 20 years ago the JB Weld display had chained to it two old valves stuck together at the head end the test was to try and part them…no-one did.

AFAIK it was a bit dark in colour.

Chemical Metal is still holding the oil cooler pipe onto the radiator of one of my Kawasaki's surprised me as the leak was fairly bad, not used it on a machine yet.

Last repair I did was with pound shop "araldite" and cast iron dust went a bit dark and took ages to harden right off.

Regards

Paul

[BrianParticipant @brian]

Depends where and how big the damage is, but have you considered drilling or end milling the damage area and machining a steel plug and setting in with Loctite 603 its oil tolerant, then machine the surface and scrape to finish.

It worked for me on a milling vice.

Brian

[Mike PooleParticipant @mikepoole82104]

Devcon make a range of metal repair materials, eye watering prices though!!

Mike

[Peter G. ShawParticipant @peterg-shaw75338]

Well, went to "Buy and Queue" (like that, I do) only they didn't have any of the regular. Lots of other stuff, but not the genuine Araldite.

Went next door to Halfords (aren't they the same chain these days?) and found some Araldite Standard Professional or some such. Anyway, didn't buy – thought I'd look elsewhere first.

But thanks for the idea Roy.

Regards,

Peter G. Shaw

[TerrydParticipant @terryd72465]

Posted by Peter G. Shaw on 27/02/2012 11:29:21:

Well, went to "Buy and Queue" (like that, I do) only they didn't have any of the regular. Lots of other stuff, but not the genuine Araldite…………………….

Regards,

Peter G. Shaw

 

Hi Peter,

It is available, try here for example. A simple google search found lots of places selling it.

Regards

Terry

Edited By Terryd on 27/02/2012 12:04:02

[Gray62Participant @gray62]

Probably the best range of araldite I've found is stocked by RS Components.

Oops, that embedded link didn't work ( this new editor does not seem to work for links as the previous one did.

try this : http://uk.rs-online.com/web/c/?searchTerm=Araldite&cm_mmc=UK-PPC-0212-_-02_2_MRO_Araldite-_-Araldite_Supply_Terms-_-Araldite

CB

Edited By CoalBurner on 27/02/2012 13:27:34

[The Merry MillerParticipant @themerrymiller]

Tilgear, in their latest clearance catalogue, have epoxy putty sticks on special offer.

These have the hardener incorporated in the core of the stick, the one that you need is called the "Steel Stick"

Ideal for castings, price £7.14 at the moment.

Len. P.

[TerrydParticipant @terryd72465]

Hi Again,

Araldite 'Precision' slow setting available here for less than £4.00 post free.

Hi CB, link method works for me, just highlight the word, add the URL in the box after clicking 'Link' icon and select target window.

Terry

Edited By Terryd on 27/02/2012 15:49:50

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