# Filling deep scratches in lathe ways?



## CarlosA (Jul 19, 2021)

So I dragged home a very nice 13" South Bend last night. I was quite surprised that the ways are in nice condition with no ridge or tightening saddle along the whole length of the bed. However it does have a few deep scratches and a bump from a chuck or something like that.

In order to avoid dragging more dirt and chips under the wipers i`d like to fill these scratches. Is this a bad idea? Is there a better way? What do I use? Epoxy was my first guess...

Pics attached.


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## benmychree (Jul 19, 2021)

I have heard of grinding out the scratch with a narrow cut off wheel into a dovetail shape and peening in a soft metal such as solder or babbit metal metal and finish scraping it down flush with the way surface.  I suspect that some sort of epoxy could also be used.


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## tq60 (Jul 19, 2021)

Epoxy will do.

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## markba633csi (Jul 20, 2021)

Scrub it out well with lighter fluid or alcohol before applying the epoxy, and give some gentle heat for a few hours to help cure it
You could even add some fine metal shavings to the mix
-Mark


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## tq60 (Jul 20, 2021)

Metal not needed here.

Just fill the void and make surface match.

Use good epoxy and thin a bit with acetone.

Experiment with the mix on something first.

Apply then place tape over to hold in place and flat.

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## CarlosA (Jul 20, 2021)

Thanks guys, funny how you all are from California - I lived in Turlock most of my life and recently relocated from Portland to Houston.


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## MrWhoopee (Jul 20, 2021)

CarlosA said:


> Thanks guys, funny how you all are from California - I lived in Turlock most of my life and recently relocated from Portland to Houston.


It's a small world. I came from Modesto myself, still have clients in Turlock. Worst street layout I've ever seen.


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## Richard King 2 (Jul 20, 2021)

If you don't grind the scores deeper and wider at the bottom to anchor it in, just filling what's there will fall out,  I would use Devcon aluminum as it dries and looks like cast iron.  It will be soft.  The ideal way to do it would be to gat the bed ground or planned.   I have seen where people file off the ridge, so it not being their doesn't mean much.  If you need any more help please ask as I do this for a living.  Not a guess.  You will need to scrape new oil pockets in the bed too,  The score is from lack of lubrication then from chips under the wipers.   If you need some in-person help I have a handful of students in your area. If you message me your email address I will write them and copy you.


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## CarlosA (Jul 21, 2021)

Richard King 2 said:


> If you don't grind the scores deeper and wider at the bottom to anchor it in, just filling what's there will fall out,  I would use Devcon aluminum as it dries and looks like cast iron.  It will be soft.  The ideal way to do it would be to gat the bed ground or planned.   I have seen where people file off the ridge, so it not being their doesn't mean much.  If you need any more help please ask as I do this for a living.  Not a guess.  You will need to scrape new oil pockets in the bed too,  The score is from lack of lubrication then from chips under the wipers.   If you need some in-person help I have a handful of students in your area. If you message me your email address I will write them and copy you.



Thanks for the info, I trust your advice. What is odd on this bed is how there are none of those factory South Bend flakes I see all the time on these. Even up around the headstock.

As I do more cleaning and looking i`ll make some more decisions.


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## 38super (Aug 7, 2021)

Stone down the high spots, leave the scratches.  Good place for oil to hide.


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## Superburban (Aug 7, 2021)

But, if they are too deep, they will just hold chips, and wear down the way wipers, and slide bottom in no time. I agree with filling those.


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## markba633csi (Aug 7, 2021)

I seem to recall reading the hardened SB beds don't have flaking, only the unhardened ones

-Mark


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## rabler (Aug 7, 2021)

Looking at those pictures closely, the gouges almost look like casting defects more than scratches.  Any chance this machine has had the bed reground already, and they exposed those?


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## Richard King 2 (Aug 7, 2021)

Those are scores cause by lack of lubrication.  I have seen this in many machines before,  The metal fatigues and pulls out.  The ways also look like they are soft.  It's more common on soft ways.  On soft bed South Bend lathes.  The bed was planned, stoned and scraped for oil lubrication only or something we call "square cutting"  it breaks up the surface so it had oil pockets in the bed ways.  Then the saddle and tailstock were scraped with bluing to match fit the bed.

The following explains it to the Engineers.  It's way above my pay grade...lol:


			https://www.egr.msu.edu/classes/me471/thompson/handout/class13_2005SFatigue.pdf


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