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Painting an old lathe - how do you do it well

marcsO

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Wanted to post a new thread to see how you guys restore and paint lathes, I've recently acquired a Schaublin 135 which may require re-painting, this is not a foregone conclusion yet as there is no doubt a lot of work involved in doing this.

I have a few friends who are in the car painting trade and wanted to get some idea as to what might be involved, the process, which paints, how best to apply them etc.

Stripping:

Watching You Tube there are several methods used but it seems paint stripper is the most popular, is it? How about shot or sand blasting? Any other ideas and what is best?

Preparation:

Again some machines seem to require copious amounts of filler as the castings are poor, I'm assuming if you use stripper this will soften the filler already there so it will need to be removed? How are Schaublin stands under the paint, good or bad?

Paint:

What type, best brand, 2-part, epoxy, enamel etc? I would imagine spray painting is going to achieve the best finish, do manufacturers use this method or are they hand painted with rollers or sponge/bristle brushes?

Pictures, comments, suggestions and tips are all welcome as this process is long, dusty, time consuming and hard work so the thought behind this is to get the heads up to ensure its not as painful as it could be!

If I paint mine which is a pale blue/silver colour (Hammerite finish on the steady accessory) currently, but I am thinking of going silver all over with polished metal surfaces where left this way, will a metalic finish be harder and less durable than a solid colour like the green etc?

Excited to here all your techniques and tips.

Marc
 
Stripping:

Watching You Tube there are several methods used but it seems paint stripper is the most popular, is it? How about shot or sand blasting? Any other ideas and what is best?

If you are repainting a older machine with original paint then it's not to your advantage to strip everything down to bare metal. Just smooth it down like in
auto body work. The only thing I can see about a full strip is that you can say you did it. There may already be filler in your cast pieces. Using stripper may
remove the contours on the metal and you will have to rebuild them back.

Preparation:

Again some machines seem to require copious amounts of filler as the castings are poor, I'm assuming if you use stripper this will soften the filler already there so it will need to be removed? How are Schaublin stands under the paint, good or bad?

??????

Paint:

What type, best brand, 2-part, epoxy, enamel etc? I would imagine spray painting is going to achieve the best finish, do manufacturers use this method or are they hand painted with rollers or sponge/bristle brushes?

I use two part industrial quality DuPont with a fresh air system. I spray but the paint can be rolled or brushed. I migrated from rattle can paint because I didn't
like the durability. Supposedly a breathing mask is all that is needed with a brush or roll job.

It's a lot better to hold off on the paint job until everything is 100% working first. Unless you have gone through fixing the same machine a few times before.
 
Rons appreciate the comments.
I will certainly do all the checks first to ensure the machine is right and 'worth' time and investment in paint should that be the case.

??????? - Question around Schaublin castings really, are they decent, average or quite poor under all the paint?

Marc
 
Media blasting of any kind should be avoided unless you are taking the machine down to nuts and bolts. That stuff gets everywhere and you'll never get it cleaned out of all the places it will hid. Taking a machine down to the bare castings is opening a pandora's box. If the base filler is good then clean the oils and greases off the machine, sand/wire brush the machine to move loose paint and scuff the surface. Clean the machine again, then clean it a 3rd time. Maybe even a 4th time LoL. Then paint the machine.
 
Mike totally agree on the media blasting comment, certainly the stand once clear of motor and pulleys and electrics should not be too hard/sensitive to a good clean and would be IMO ideal for a media blast if that was the decision, from experience with fillers and paint often they react when different chemistries are used so while leaving some on is certainly a great plan to avoid more work it may create more problems than it fixes.

I'm sure there are some here who have done these jobs and can advise if there are issues...

Marc
 
The "best" way is to completely disassemble the machine so that it is painted in the same manner as it was originally. But you run into the same problems as repainting a car: EVERYTHING must come apart. Very few automotive repaints are done this way as it is just too labour intensive. For a lathe I would mask off the machined parts and paint over what exists unless it is completely peeling. As for the body filler, I would just replace it if needed and paint over it.
 
My plan is first understand if the lathe wear is within tolerance and no major items like a bed re-grind is needed, if its OK then I will remove and clean all the parts that are easily accessible, replace belts, wipers and flush out the oils and all that stuff, check all the electrics and brake etc, once that is done I will clean up the existing machine bodywork and see how it come out, if this is not good then my plan would be to totally strip the machine and re-paint. At this juncture I would totally disassemble everything and re-paint, that is why your replies and advice around the re-paint methods and what to do and not do are so important as never having done paint on a lathe means I'm relying on you all.
For me if its to be done it has to be done right, period.
 
It is customary and beneficial that machine tool elements made from cast iron are filled and painted. The filler acts as a damping medium for both vibration and protection from impact.

Do NOT strip sound filler and paint from the castings. Spot abrade local defects, and then refill and smooth (Bondo)

Then repaint.

My 2cents, as has been shared by others.
 
I would strongly advise against stripping. My opinion is that in most cases it is wasted time and effort at best. At worst you end up with an inferior result or a giant mess. Schaublin paint of this era is easy to sand and makes an excellent base coat so long as it has not failed (peeling or lifting). Thoroughly sand and feather edge or spot fill chips or gouges (U-Pol Dolphin glaze is excellent for this). I top coat directly over original paint but you can also apply additional primer surfacer if desired. If you do, it is necessary to sand again. Always use 2k products if you are able. Sherwin Williams Polane T is my top coat of choice but I'm not certain it is available in the UK. If you can't find it an automotive 2k single stage urethane is suitable if you ask the stockist to add a flattening agent (between 25-75% gloss). Besides being highly impractical, full gloss doesn't look nice on machine tools of this era. Spraying is probably the best method overall but I have seen very respectable jobs done with brushes and rollers. Thorough cleaning of the machine, sanding, proper masking and preparation are paramount.

It's a LOT of work and quite costly to do it properly.
 
large ones I don't bother, chips and coolant soon makes it look like it did before. Little guys, sand sand sand, paint, sand sand, paint. dont' strip or blast. everything come comes apart and gets masked. I bend coat hangers into S's and hang parts on rods. I spray ppg line 7 paint with an airbrush, talc added to get rid of the gloss. If for whatever reason a coat isnt good enough for you, sand and repaint

one is Schaublin, one I made

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I sanded back thoroughly with 120 grit paper and washed everything a few times with thinners, including using Acetone on some of the more problem areas, eg where paint was cracked but not flaking.
Agree with others, definitely do not strip. All done with brush using a good quality 1 part epoxy enamel.

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Lovely work Pretzel, do you have a close up of the paint as to how smooth the finish following the brush application?
Are you able to outline what type of brush and how many coats? Any sanding in-between etc?
Paint brand?

marc
 
Lovely work Pretzel, do you have a close up of the paint as to how smooth the finish following the brush application?
Are you able to outline what type of brush and how many coats? Any sanding in-between etc?
Paint brand?

marc
Get the best quality brushes you can afford and luckily I did have a 20mm Sable hair brush from other work and used that for the details. You do need something with more flexible hairs for details.
One coat of primer and 2 topcoats and used a tack cloth for the topcoats.
Initially I was thinking spraying with 2 part but gave up on that idea when I recovered my sanity.
With brushing it's impossible to avoid getting some detritus in the finish and I am picky over things like that but this did turn out good enough.
With this type of work it's best not to try it with previously used brushes unless you are obsessive with the cleaning of them.
I'll post a photo later.
Yes I sanded primer and 1st topcoat with 800 wet and dry.
 
large ones I don't bother, chips and coolant soon makes it look like it did before. Little guys, sand sand sand, paint, sand sand, paint. dont' strip or blast. everything come comes apart and gets masked. I bend coat hangers into S's and hang parts on rods. I spray ppg line 7 paint with an airbrush, talc added to get rid of the gloss. If for whatever reason a coat isnt good enough for you, sand and repaint

one is Schaublin, one I made



uvxKHfs.jpg


Nice work. What is this?
 
thanks.....its a Hauser M1 Jig borer. Swiss, about the best made tool I've worked on. feedscrew dials are graduated in tenths with mechanical lead error compensation, neat little machine. The spindle isn't in this shot, not installed yet. you could have various attachments (spindle, microscope, punch/scribe) that could be swapped out. Each were lapped to an individual machine.
 








 
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