# Pm932 Base Mod



## 65Cobra427SC (Sep 12, 2015)

Note: Thread was renamed to PM932 Base Mod

Wasn't sure what else to call it but the picture shows how oil can form a pool within the indentations along the sides of the PM932 mill. Not sure if other mills are this way but they could be since I think the indentations are there to help strengthen the casting. But in my case they helped create a problem. The oil found it's way under the paint during the boat trip from China and the end result is the filler underneath the paint became oil soaked, causing the paint and filler to separate from the cast iron. My plan is to clean those areas down to the metal so I can repair and repaint the affected areas.

Since I have to do the work anyway, I'm also thinking of filling those indentations with epoxy in order to prevent any further pooling. I could even shape the epoxy so the oil runs off the side in a specific location. Just wondering if anyone else had this problem and/or has a better idea how to fix this. Thanks.


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## brav65 (Sep 12, 2015)

I am not sure epoxy is your best option. I would look at Fiberglas reinforced bond. It cures up pretty hard but can be sanded and shaped.


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## 65Cobra427SC (Sep 12, 2015)

Not committed to epoxy but would want to use something that won't separate from the metal and isn't going to be affected by oil which eliminates the majority of products. Considering where that area is located, it will likely get oil soaked on a regular basis. I also can't make that area completely level so the oil doesn't work it's way elsewhere... i.e. under the bolt heads. I searched online for options... hadn't considered fiberglass but not sure I want to go there. Now I'm considering Lab-metal by Alvin Products which is a 1-part filler... goes on with a putty knife... air dries in a few hours... and is "not affected by petroleum-based oils or gasoline".


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## wrmiller (Sep 12, 2015)

My 12z has similar troughs and I watch them when pulling the oiler handle. When the oil starts oozing out from under the saddle I figure I've got enough oil in there. 

I've not had any problems with them though, and I like the fact that they catch oil for later sopping up with a paper towel instead of running down the side of the machine.


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## 65Cobra427SC (Sep 12, 2015)

Interesting... thanks for the input. In my case the oil would just run down the sides into the channel around the top of the base, then into the container where it belongs.


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## tmarks11 (Sep 12, 2015)

Why not just bondo?  Essentially polyester resin with a filler made of chopped silica.  That is what all the other voids in the casting (that you can't see because they are painted over) are filled with.


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## brav65 (Sep 12, 2015)

Auto correct change bondo to bond.


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## 65Cobra427SC (Sep 12, 2015)

tmarks11 said:


> Why not just bondo?  Essentially polyester resin with a filler made of chopped silica.  That is what all the other voids in the casting (that you can't see because they are painted over) are filled with.



Since cast iron isn't smooth, it was obvious a filler was involved even before I purchased the machine. And most old cast iron machines had some kind of filler, even the Bridgeport, but it's the type/quality of the filler that's important. I expected less from a mill made in China than Taiwan but I didn't expect to be removing softened filler from a new machine either. But I'm not regretting my purchase in the least... things like this happen and even though my situation is worse than most, I can fix it. It's just it wouldn't make sense to do all this work only to use another filler that could end up doing the same thing. Bondo, as well as other fillers of the same type, contains talc which absorbs moisture... and besides, they are not oil resistant. It's the paint that shields the filler on these machines. But if the oil finds a way under the paint, the filler will absorb it and the process eventually spreads.

The reason my situation was much worse is because the oil was working it's way under the paint along the entire top edge where the paint ends. There was actually a gap between the paint and the cast iron all along that edge and the filler was still soft into the trough. I knew how much of the paint/filler to remove because the filler would gradually get harder. So instead of using Bondo, I'm hoping Lab-metal will do the same but it's resistance to oil will at least help prevent this from happening again.


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## 65Cobra427SC (Sep 21, 2015)

There were multiple complaints about Lab-metal online so I decided to purchase it locally instead. Tried 2 different retailers and in both cases we opened the cans and found they were only 2/3 full and as hard as a rock. The label says the factory can has a 2-year shelf life but there is no date or date code on the can or the label anywhere, duh! So none of the retailers know how old they are. Went back to the epoxy idea and although it's working very well, it's taking longer for me to finish than I planned, although I'm juggling it between other projects. I'll post pics within another couple days.


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## 65Cobra427SC (Oct 8, 2015)

The base mod is done, including paint and a two part clear coat that's chemical resistant. Now I can get everything else connected and I'm ready for the lathe. In addition to modifying and repainting the base, I fixed a damaged area on the back of the column where the DRO mounting bracket gets attached, and repainted the long cover that bolts to the back of the column. They put primer on one side of that cover, then painted the opposite side... so there was no primer under the paint and it was peeling off. Now it's done right.

One thing the pictures don't show is I removed all the paint and filler around the trough and bolt holes as well. Otherwise they should be self explanatory but I doubt anyone else is crazy enough to do this. It was very relaxing for me and now the oil will just roll right off the sides and into the oil channel on the stand.


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## coolidge (Oct 8, 2015)

It looks great Cobra!


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## TomS (Oct 8, 2015)

I was thinking of grinding a couple of drain slots into the outer lip on each side of my mill.  I like your idea of filling the coolant trough better.  Nice job!

Tom S


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## 65Cobra427SC (Oct 8, 2015)

Coolidge... Thanks.

It looks really good... definitely not perfect but that wasn't my objective.

Before I filled the troughs I made sure the base was level so the 1st layer of epoxy would settle that way. In order to apply the 2nd later of epoxy, to create the slopes, I had to do one side at a time. I did two things... I mixed the epoxy a little longer to make it a tad bit heavier... and I tilted the machine using the levelers. To do the right side of the base, I raised the right side and lowering the left side. This helped keep the epoxy at the correct slope. For the left side, I did the exact opposite.


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## 65Cobra427SC (Oct 8, 2015)

Thanks Tom

I considered the exact same thing but had no clue if grinding slots would weaken the casting enough to crack. And I had to remove the paint/filler in the troughs anyway, so at that point I decided it would be best to just redo the entire area and create a slope. But going that route took more hours than I care to admit. Then there is the cost... lots of epoxy... paint matching and putting it into spray cans... and a more expensive two part clear coat that comes in a single can. But I'm anal... and considering I thought it was fun, also sick.


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## TomS (Oct 8, 2015)

65Cobra427SC said:


> Thanks Tom
> 
> I considered the exact same thing but had no clue if grinding slots would weaken the casting enough to crack. And I had to remove the paint/filler in the troughs anyway, so at that point I decided it would be best to just redo the entire area and create a slope. But going that route took more hours than I care to admit. Then there is the cost... lots of epoxy... paint matching and putting it into spray cans... and a more expensive two part clear coat that comes in a single can. But I'm anal... and considering I thought it was fun, also sick.



Good point about weakening the casting.  I'll stand on my head and look at the underside of the base casting.  

Tom S


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## 65Cobra427SC (Sep 21, 2019)

Was browsing and figured I would just give an update. It's been 4 years since the above modification and everything still looks perfect. I wondered back then if this project would be worth the time and effort, let alone the extra cost for using epoxy and a high end clear coat, and no doubt it was. The base wipes clean every time


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