Stain on Mill Table

[electrosteam]

Hi,
I have a stain on my mill table with a thin line following exactly the outline shape of the milling vice that had been clamped there.

Small vertical mill, FB2 clone.
Interposing bedding sheet of paper that had been discarded from my wife's volunteer activity printing.
Standard (cheap) A4 Bond paper.
Could be inkjet or laser machine.
Print side down to the table.
Vice installed for about a week.
Intermittent milling for an hour or so each day.
Soluble oil in turpentine as a coolant (1 oil to 8 turps) on MS cutting.
Mill has never seen water based coolant.
It is winter here (Sydney) with temperature down to 5 degrees C at night.

Any thoughts on what can cause the stain ?

Turpentine drawing chemicals out of ink or paper ?
Condensation along the outline edge that affects the paper in some way ?
Inkjet ink picking up moisture ?
Acid in paper leaching out ?

Does anyone else use bedding sheets of paper ?

What should I use as a bedding layer ?

Happy machining,
John.

 

[gbritnell]

Hi John,
I've never heard of using paper as a bedding sheet between the mill table and vise. In my years of machining I've taken some very large cuts with some very large machines and cutters and have never had a vise move on the table. I have used paper between the material that I was cutting and the vise jaw to prevent it from moving when there was a small surface area to clamp to. I suspect that being as it is cold in your shop if you turn on a heater the condensation is being trapped in the paper and therefore causing a mild rust stain.
gbritnell

 

[kvom]

I mount my vise directly to the table. At school I was told that a vise that is clamped long term to the table can cause crevice corrosion, and that to prevent it a thin layer of oil is applied to the table before installing the vise. The vises are all removed and reinstalled every 3 months as part of thoroughly cleaning the mills.

 

[Tin Falcon]

John:
My guess would be a reaction between the acid in the paper the the water in the coolant the steel in the table and some O2 from the surrounding air. When I ran a CNC lathe in a shop we had to be careful of leaving the coolant sitting one the ways. IIRC every night the lathe was wiped down and all exposed metal oiled with way oil. We were especially careful the Friday of a long weekend. It may be just the paper holding the H2O around the edges and causing minor rust /staining.You may want to soak the paper in oil before putting under vise or use gasket paper.
Tin

 

[steamer]

Tin's advice about oiling the paper is a good one...it really does keep the vice locked down and if it is full of oil it wont absorb water.

Dave

 

[seal killer]

All--

Who would have thought that my very first post on this forum would concern a vise vs. mill table issue!

I am a TOTAL NEWBIE concerning steam engines and joined this forum to learn . . . especially as I build my first one.

But, about that stain . . .

I have only been milling for a couple of years. The vast majority of that time, all my work was done in aluminum using WD40. Lately, I have been working with 4140 using Tap Magic. I am told that Tap Magic will either leave a stain or promote a stain if not completely removed from the table and its environs. I wonder if other cutting fluids share this undesirable feature?

The tram on my mill is very, very good. The vise (D675) is also aligned extremely well. I would certainly hate to remove that vise and clean beneath it once or twice a week. But, is that the recommendation?

Thanks!

--Bill
PS I haven't had an opportunity to fill out my profile, but will shortly.

 

[Maryak]

Bill,

Welcome to our forum.

Best Regards
Bob

 

[mklotz]

Hi Bill,

Welcome aboard. I always enjoy your posts over on the Chaski forum.

This is indeed the place for model engines. You'll enjoy the time you spend here.

 

[vlmarshall]

Welcome to the forums!

The vise (D675) is also aligned extremely well. I would certainly hate to remove that vise and clean beneath it once or twice a week.

Do it! Not only will you keep your table clean, you'll also:
1. Keep chips from building up in the T-slots under the vise,

2. Be sure your vise is always square,

3. Not get in the habit of assuming it IS square before you start working,

4. Get so familiar with squaring a vise that it takes hardly any time,

5. Become so comfortable with setting up the vise straight, that setting it up at an angle becomes a valuable addition to your list of tricks.

 

[seal killer]

Bob and mklotz and Vernon--

Thank you all very much for the welcome! I have to admit being rather spoiled over on chaski, but this forum appears just as gentlemanly as that one. I am here to learn and I know almost nothing so you have your work cut out! I am sure you are used to it . . . and all the questions that have been answered a thousand times in a thousand different ways.

mklotz, it was someone on the chaski forum that recommended this one. I immediately took that recommendation.

Vernon,

Do it!

Ok. I will. It will be interesting to see if there is a stain on my table. The Kurt has not been removed and replaced for about a month; that was when I started my last project and wanted to make sure that baby was dialed in. I will r&r it for all of the good reasons you suggest.

I am going to start a thread concerning my first attempt at building a steam engine. It might be interesting because I do not have a lathe. I hope all of you and others have suggestions, because I am sure going to need them!

--Bill

 

[mklotz]

First suggestion... Get a lathe!

While I suppose it's theoretically possible to build a model engine without a lathe, it's going to be devilishly difficult. Personally, I think it's a *practical* impossibility - especially so for someone who's never built an engine.

 

[seal killer]

mklotz--

Regarding your first suggestion: I think you copied that from the Chaski board!

I just began a thread regarding the Minikin. Take a look and tell me what you think.

--Bill

 

[tel]

Hi,
I have a stain on my mill table with a thin line following exactly the outline shape of the milling vice that had been clamped there.


It is winter here (Sydney) with temperature down to 5 degrees C at night.




Does anyone else use bedding sheets of paper ?


John.

Oi John. Don't worry to much about that stain, in the fullness of time it will join up with all the other stains and become undetectable.

Down to 5°C at night? 'ere in Rockley it's doing well to get up to 5°C thru the day - we all down tools and go skinny dippin' in the crick when it does!