# Cast Iron while its out for repair should I redo this braze?



## woodchucker (May 4, 2017)

I am sending this out to a kid who did an excellent weld (not braze) on my 8520 brake. I asked him to weld it if he could with nickel as an old time welder told me nickel.  He heated it and welded it.. beautiful.

Now I bought this taper attachment, I probably shouldn't have as it has so many issues. It was cracked and brazed , and was being offered for less. It looked good enough to use, but it had cracked ways on the dovetails. I ground out the old studs and damaged area, since I want to fix and get new grub screws in there.  Whoever did the repair used small grubs and relocated them. That didn't bother me, but the cracks did.  So while he is doing the ways, should I have him redo the previous crossslide repair. It looks like copper based, not silicone bronze, as I would have expected. Once I took the paint off, I  was bothered by the color.  

The funniest thing, the pic in this http://www.lathes.co.uk/south-bend-boxford-taper-unit/ is the unit before the break that was repaired. So this may have made it's way from the UK. The unit is awful.  I should not have bought it. But now it has to be turned into a user, as I can't pawn it off on someone else.

I have more cleanup to do, just finished stripping it.


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## wawoodman (May 4, 2017)

If you have a guy who will do it well, go for it. Otherwise, it will **** you off every time you look at it. Even if no one else would notice, you will.


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## markba633csi (May 4, 2017)

It looks like it should have some additional "sister" pieces of steel or iron brazed in on both sides of the cracked area to give it more strength, it seems very likely to break again in that same area unless you do some heroic measures.  Better to go for the maximum strength and to heck with keeping it looking stock.  My two cents.
Mark S.


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## Ulma Doctor (May 4, 2017)

make lemonade from lemons, if you can.
alignment of the broken parts will be tricky to maintain, but if the guy welding it up is competent- he can stick it back together again.
i'd like to see the finished repair


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## cathead (May 5, 2017)

I would like to have been the fly on the wall watching the operation that broke that part.  There isn't a huge force exerted on 
the part in use as far as I can see.  Also, when making tapers the feed is slow and depth of cut is small.  I would run it and see how
it works as is and fix it if would happen to break again.  Looking at the repair it looks it could be welded with cast iron rod
and touched up with copper or brass afterwards.  I have seen brazing that looks like copper if the zinc boils off some leaving an alloy
with more copper behind.  It's your machine so you can do as you please of course.  I find it quite interesting when a group looks
at the same post and a wide range of cogitation comes to light.  You mention cracked ways on the dovetails which would be more
of a concern to me than the repair as that would likely affect linearity.   Anyway, now you have another angle to ponder.


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## Rustrp (May 5, 2017)

The part looks like it may have been TIG welded because an oxy/acety brazing job wouldn't cause undercut on the edges. The problem with using Ni based electrode (before I go and say I would use Ni) on this part is the removal of all the bronze. It must be removed, otherwise leave it, clean it up, reinforce it, etc. 

For a non-machinist I would weld it up with nickle based electrode and finish it as close to dimension as possible. For the machanist I would use runoff tabs to help keep the part straight and leave all the excess material on and allow the machinist to mill the excess off. 

Welding cast iron is all about good days and bad days. The good days are those when the part doesn't have extra high carbon content in the area to be welded.


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## 4GSR (May 6, 2017)

If it was me, I'd buy a piece of rectangle cast iron the right length and make a complete new slide.  Wouldn't take much provided you have a mill and the appropriate tooling which I have.  I don't need another project....


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## scwhite (May 6, 2017)

cathead said:


> I would like to have been the fly on the wall watching the operation that broke that part.  There isn't a huge force exerted on
> the part in use as far as I can see.  Also, when making tapers the feed is slow and depth of cut is small.  I would run it and see how
> it works as is and fix it if would happen to break again.  Looking at the repair it looks it could be welded with cast iron rod
> and touched up with copper or brass afterwards.  I have seen brazing that looks like copper if the zinc boils off some leaving an alloy
> ...


I would like to go back to when and where it got Broke also and if I was guessing and I am guessing 
But in my  opinion it most likely got broke while someone was trying to move the machine or load it in a truck or trailer or unload it . Moveing machinery 
Is the most common way that cross feed screws and hand wheels . Gear box handles , tail stock hand wheels get bent or broke . 
      Just plain under tooled to move the machine 
Properly.


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## woodchucker (May 6, 2017)

Or it could have been during shipping of the part. I don't believe it is an original South Bend as originally advertised either. There's no SB label, no SB part no.
It looks like a knock off that someone did up. The cast iron, is not the same granularity of other SB cast irons. This has a very smooth finish, and was not machined where SB would normally machine things. The paint covered a lot of those issues.  That paint was pebbly and tough stuff to remove. There were enough screws and the gib plate that were rusted, or pitted. I don't see wearn (nothing is smoothed from wear) , so this may have never been used, and may have been dropped while handling. For it's lack of use, it's in rough shape.


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## 4GSR (May 6, 2017)

woochucker said:


> Or it could have been during shipping of the part. I don't believe it is an original South Bend as originally advertised either. There's no SB label, no SB part no.
> It looks like a knock off that someone did up. The cast iron, is not the same granularity of other SB cast irons. This has a very smooth finish, and was not machined where SB would normally machine things. The paint covered a lot of those issues.  That paint was pebbly and tough stuff to remove. There were enough screws and the gib plate that were rusted, or pitted. I don't see wearn (nothing is smoothed from wear) , so this may have never been used, and may have been dropped while handling. For it's lack of use, it's in rough shape.



It's definitely South Bend.  Unless someone bought it thinking it is SBL and actually from a Dalton lathe, but I don't think so.  I had a 9" SBL I reconditioned that had the taper attachment, it had this same cross slide piece.  Fortunately, it was in decent shape and not broke up and butchered as this one is. 
If your not in a rush, I'm sure they come up on ePay often, buy one to replace this one with.  Will require some scraping and fitting to get it right for your lathe.  Ken


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## sanddan (May 6, 2017)

If you do need to redo the braze/weld you could insert 2 dowels in the thicker area which would help in the alignment and also add strength to the joint.


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## Silverbullet (May 6, 2017)

Knowing some of the properties of cast iron , do you want to risk it , to mill out through the braze your losing an inch of length +- , I would smooth out lumps on the braze and repaint. Once it's painted no one will notice eventually you'll even forget it's been repaired. But it's up to you if it bugs you bad enough to get rebrazed , why not make a new one . Straight forward machining , cost of materials I bet less then the braze up. , good luck with the repair.


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## woodchucker (Jun 7, 2017)

Whatever the material is that welded it, it's pretty hard. 2 flute didn't like cutting it. had to use a 4 flute, and even that didn't like it.  Didn't feel like pulling out a carbide end mill for this.

So I started working on this a little more now that I have time. The weld is not  aligned dead flat. the end drops down. So I started fly cutting the casting to level it. I've reached the max I want to go that way, still 25 thou out.  I will take some off the mating part. I had to shim it to keep the chatter down to a minimum. It chattered a little because of the interrupted cut across the slot and distance unsupported from the flat to the supported shim.

I found that the other pieces of this taper attachment are not well made. This is not a southbend taper attach. it has to be a knock off. The part that attaches to the ways is not cut for the ways well. it wants to drop the taper too low and away, and force it out of alignment. Considering having it weld filled, or filling it with epoxy and re-cuting the Vee.  pics to follow


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## dlane (Jun 8, 2017)

Did it all fall down and break at some point, maybe forklift damage, should be able to make it right .


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## jsh (Jun 8, 2017)

I have seen a lot of different rod alloy types that were said to be the latest, greatest and the last word in welding up cast iron. A couple of friend fool with a lot of old tractors. Carburetor sand exhaust manifolds were always sought after parts. They came up with some kind of rod that would weld about anything and do a pretty decent job. It looked like brazing rod, but after welding the stuff got real hard. 
It also flowed into the pores of the cast iron way more than any brazing rod I ever saw. 
As mentioned the brass will have to be ground out in order for the nickel rod to do a good job. 

If all the parts are there and it is a knock off of what you are after, looks like a good pattern for a new build. 
Jeff


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## tq60 (Jun 8, 2017)

2 plans of attack.

One...If not correct then look for correct one...

Two...take this one to a mill and on the bottom side cut a pair of slots lengthwise through the break and either epoxy or braze in a suitable brace that just fits into the slots.

Maybe cross drill and tap in some roll pins.

These things simply hold it in place and the forces are not cross to the unit so it will hold up fine.

Once this is all done time for "body and fender" work.

File or grind off the high spots and use body filler to return it to shape.

Cover work on bottom and fill all holes then paint.

It will look as good as you make it and will work just fine.

Sent from my SAMSUNG-SGH-I337Z using Tapatalk


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## woodchucker (Jun 8, 2017)

dlane said:


> Did it all fall down and break at some point, maybe forklift damage, should be able to make it right .


no idea, I bought it that way.
I don't want to crack it at this point. I've decided to live with the current weld. Hence the fly cutting to straighten it out.
The epoxy fill would be the V for the holder that holds the ways. I think I am going to use plumbing epoxy (the hard stuff you knead to mix) I'll put a coat of wax on the ways, and also cover with saran or wax paper then stuff the vee and lock it down, holding it in position so it doesn't slip down like it wants. Then if necessary I'll machine it.
That way I get close to begin with. I'll put a registration mark on both sides and take measurements just in case I have to go full bore machine it.


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## brino (Jun 8, 2017)

jsh said:


> They came up with some kind of rod that would weld about anything and do a pretty decent job. It looked like brazing rod, but after welding the stuff got real hard.It also flowed into the pores of the cast iron way more than any brazing rod I ever saw.



....and this product was what?
You can't torture us with that description and then not tell! 
-brino


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## woodchucker (Jun 8, 2017)

it's a taper attachment that I should not have bought from the seller. It's just got so many issues. I just spent all night working out the problem with the way holder not being aligned correctly.  Some plumber epoxy helped  Still not perfect, but now it's close to lining up on it's own.


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## jsh (Jun 9, 2017)

Brino, I first saw this stuff at a farm show in the mid 80's. I thought it was some snake oil sales type stuff. Then a large metal shop had some in stock. 
My boss at that time bought some, seems like it was several dollars for each rod. We welded up a exhaust manifold on a piece of equipment, while it was bolted to the head. Later that year after it had been used just patched up all season we took it off and welded up the rest of the crack. It was gouged out and cleaned up good of coarse. 
It looked like brazing rod,yet it seemed like it would spark a little when hit with a grinder. 
If I can find out what it was I will reply. 
Jeff


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