Thread: Re-painting a lathe?

Does anyone have a view on type of paint to redo a lathe. I intend to do both of mine but not at the same time. I have 5 years experience with spray work on guitars and would like to have a good finish so spraying is my 1st choice. With the guitar work it was all nitrocellulose which was very user friendly and trouble free but won't use that in this case.
Was thinking 2 part but then maybe not.
Can't avoid considering a good quality 1 part epoxy enamel, although easy, isn't very durable. I've used 2 part Dulux structural paints in the past but...In a confined workshop?

At a place I work 2K paint is used. It has a lot of safety implications and a lot of these get ignored at times on littlejobs. It is my understanding that breathing the stuff is the main point of ingress into the body but it is absorbed in smaller quantities through the skin and eyes. Some people will be more sensitive to it than others. Also don't forget your families, neighbors and dog. This stuff travels on a breeze and may effect others around you. But 2K does give a nice hard wearing finish.

My choice was to use a single pack paint. I used Dulux metal shield on my mill and they would tint any of 20 0000 coulours. It worked well but I think there may be better single pack options, I just have not used them.

In the end I brushed mine and am happy with the job. The average lathe will not be as smooth as the average car. Therefore any blemish will show on a quality 2K paint job on a lathe. I also find but cant say why, that the brush job looks more natural, it seems to have depth and works. For me I found brushing to work well as I had a lot less masking up to do and did not have the worry of overspray.

I have one scratch but it is holding up well.

Steve

There a few specific issues to bear in mind when painting machinery, from my own limited experience and research. The old finish probably will be well and truly penetrated by oil, right down to the castings, and the oil penetrates the cast iron and can make it difficult to get stuff to stick at the metal-to-coating level. Oil can even be seeping through from inside the machine (gearbox etc) and make your coatings peel away a couple of years after you do a great job. Then there's the bog- the standard way of dealing with a rough casting finish is to cover it with HEAPS of body filler, which will all need to be removed and re-done. The other thing is that your finish needs to be resistant to cutting fluids and lubricants. Most paint places will have no idea about that last bit. I used an industrial enamel on my lathe about 8 years ago and it has been penetrated and stained by oil, and anywhere the flood coolant runs over it it has acted like paint stripper. I used a 2-pack enamel (sprayed) on my Bridgeport conversion which gave a great finish and seems to be holding up better but it is early days yet.

Originally Posted by Reidy41

At a place I work 2K paint is used. It has a lot of safety implications and a lot of these get ignored at times on littlejobs. It is my understanding that breathing the stuff is the main point of ingress into the body but it is absorbed in smaller quantities through the skin and eyes. Some people will be more sensitive to it than others. Also don't forget your families, neighbors and dog. This stuff travels on a breeze and may effect others around you. But 2K does give a nice hard wearing finish.

My choice was to use a single pack paint. I used Dulux metal shield on my mill and they would tint any of 20 0000 coulours. It worked well but I think there may be better single pack options, I just have not used them.

In the end I brushed mine and am happy with the job. The average lathe will not be as smooth as the average car. Therefore any blemish will show on a quality 2K paint job on a lathe. I also find but cant say why, that the brush job looks more natural, it seems to have depth and works. For me I found brushing to work well as I had a lot less masking up to do and did not have the worry of overspray.

I have one scratch but it is holding up well.

Steve

Ok thanks, pretty much sums up my feelings although I don't think I'll do a brush job as much as that would be very convenient it is a drawn out business and you can't quickly and easily build up a coat thickness.
I've had the Myford Super 7 now for 25 years and though it looks a bit shabby, it does the job very well, so I wasn't too fussed over appearances until I got another lathe, which as I needed to take apart to install in the workshop, prompted thoughts of painting.
I might set up a temporary 'spray booth' out of plastic sheet to collect much of the overspray.
Even though the base alone of the new lathe weights around 260kgs each of the surfaces is quite small in area.
2 pack? Don't know, but I do appreciate the benefits of thicker paint layers.

Originally Posted by Pete O

There a few specific issues to bear in mind when painting machinery, from my own limited experience and research. The old finish probably will be well and truly penetrated by oil, right down to the castings, and the oil penetrates the cast iron and can make it difficult to get stuff to stick at the metal-to-coating level. Oil can even be seeping through from inside the machine (gearbox etc) and make your coatings peel away a couple of years after you do a great job. Then there's the bog- the standard way of dealing with a rough casting finish is to cover it with HEAPS of body filler, which will all need to be removed and re-done. The other thing is that your finish needs to be resistant to cutting fluids and lubricants. Most paint places will have no idea about that last bit. I used an industrial enamel on my lathe about 8 years ago and it has been penetrated and stained by oil, and anywhere the flood coolant runs over it it has acted like paint stripper. I used a 2-pack enamel (sprayed) on my Bridgeport conversion which gave a great finish and seems to be holding up better but it is early days yet.

Thanks.
I've gone over the suspect paint areas with 180 paper and scraped out anything else so it'll be a job for primer/filler coat for the rest. Neither of these lathes are toolroom types so have been mostly used for precision work but I get what you're saying and once sanded will go over with thinners. Apart from missing paint in some areas most of it seems sound.

I've used the Wattyl industrial range "agricultural enamel" on most of my machines and projects. So, basically, "tractor paint". It is not 2k. There are fast dry and slow dry varieties. I get the fast dry so that in 15 mins or so I can get 3 good coats on with my not-very-professional spray gun using my not-quite-up-to-it compressor.

I'm no professional, and painting is like my least favourite thing, but I've got good results. Good enough for me anyways.

Like most paints, it is not solvent resistant - so cleaning the machine with brake cleaner is not a good thing, but oil, coolant, etc is fine and it seems to stick pretty well.

I've usually just gone down to my local Paint Spot and got a colour match done, and get them to calm the gloss down a bit for a satin finish - but not too much as I think the chalk content in the de-glosser-magic-stuff makes the end result a little more brittle.

Recently, having now been bought by Dulux, they stock only the Dulux industrial equiv. I used it recently on a drill press and it seems alright.

Greg.

The main health problem with 2 pack PU paints is the hardener which is typically an isocyanate, isocyantes have an affinity for water and there is plenty of that in the lungs. The isocyante hooks itself up with the lung's mucus lining and doesn't get breathed out, it also carries paint with it which sets and stays in the lungs. A mixture of toxicity and ever reducing lung surface eventually does you in.

Those who insist on spraying 2 pack without the right PPE should choose paint colours they think their pathologist will like.

Originally Posted by Reidy41

At a place I work 2K paint is used. It has a lot of safety implications and a lot of these get ignored at times on little jobs. It is my understanding that breathing the stuff is the main point of ingress into the body but it is absorbed in smaller quantities through the skin and eyes. Some people will be more sensitive to it than others. Also don't forget your families, neighbors and dog. This stuff travels on a breeze and may effect others around you. But 2K does give a nice hard wearing finish. Steve

Is 2K more resistant to red hot swarf than single pack enamel? If not, I'd say it provides no real benefits and plenty of drawbacks.

I agree with Reidy41 that a quality 2K finish may actually look worse on a lathe by accentuating the surface imperfections.

Originally Posted by bob ward

The main health problem with 2 pack PU paints is the hardener which is typically an isocyanate, isocyantes have an affinity for water and there is plenty of that in the lungs. The isocyante hooks itself up with the lung's mucus lining and doesn't get breathed out, it also carries paint with it which sets and stays in the lungs. A mixture of toxicity and ever reducing lung surface eventually does you in.

Those who insist on spraying 2 pack without the right PPE should choose paint colours they think their pathologist will like.

Yes, which is why, if 2 pack it might something like Acrathane, an acrylic without the isocyanates. Anyway if I go that route it'll be a somewhat brief episode and include any necessary PPE.

Modern 2 pack is a lot lower in isocyanates than the original stuff. Still wear your PPE though.
I use 2 pack in preference to any other paint system these days.
Ideally you would etch prime any bare metal areas, then put a decent coat of 2 pack high build primer on which will smooth the rough casting quite a bit, before finishing with 2 coats of 2 pack top coat. I quite like Wattyl PF330 high build primer followed by Wattyl Colourthane top coat, but there are lots of good paints out there. The Wanda paint range is one worth considering as all their paints use the same hardener and mixing ratio which simplifies life a lot and keeps costs down. Whatever paint system you choose, follow the mixing and thinning ratios religiously.
Best to use wax and grease remover to clean down with rather than thinners as it is cheaper and does a better job into the bargain.
2 pack is far more resistant to oil and cleaning products once properly cured.

Originally Posted by Karl Robbers

Modern 2 pack is a lot lower in isocyanates than the original stuff. Still wear your PPE though.

At work we use two different brands of paint. Both available of the shelf. One uses !/4 of the isocyanates as the other. The higher isocyante paint is cheaper and more readily available in more shops. Therefore please take the above statement with caution and check the SDS.

If you are spraying this at home I hope you have a large block with no close neighbors, keep the family away and chain the dog up at the other end of the block. Some people will only have a mild reaction, whilst it will create major life long issues for some others. I am sure that there are people out there that will tell you they were a mechanic for 50 years and never had a problem with asbestos brake pads. They are not available now for a reason. Isocyantes can be just as bad if the correct PPE is not used by all that comes in contact, not just the person painting.

Steve

Originally Posted by StrayAlien

I've used the Wattyl industrial range "agricultural enamel" on most of my machines and projects. So, basically, "tractor paint". It is not 2k. There are fast dry and slow dry varieties. I get the fast dry so that in 15 mins or so I can get 3 good coats on with my not-very-professional spray gun using my not-quite-up-to-it compressor.

I'm no professional, and painting is like my least favourite thing, but I've got good results. Good enough for me anyways.

Like most paints, it is not solvent resistant - so cleaning the machine with brake cleaner is not a good thing, but oil, coolant, etc is fine and it seems to stick pretty well.

I've usually just gone down to my local Paint Spot and got a colour match done, and get them to calm the gloss down a bit for a satin finish - but not too much as I think the chalk content in the de-glosser-magic-stuff makes the end result a little more brittle.

Recently, having now been bought by Dulux, they stock only the Dulux industrial equiv. I used it recently on a drill press and it seems alright.

Greg.

All very tempting to go with an epoxy enamel and a brush.
However these thoughts over painting only started once I had dismantled the 2nd lathe to get it into the workshop. It's in pieces so why stop there, I thought? I am an obsessive yet am smart enough to understand the meaning of the appropriate use of energy and materials and in this case as it is for me a once in a lifetime job, it makes sense to go with the more involved process.

Originally Posted by Reidy41

If you are spraying this at home I hope you have a large block with no close neighbors, keep the family away and chain the dog up at the other end of the block. Some people will only have a mild reaction, whilst it will create major life long issues for some others.an be just as bad if the correct PPE is not used by all that comes in contact, not just the person painting.

Steve

Brings back memories of when i was in business about 25 years ago. We wanted to move to 2 pack paints and during a regular inspection from worksafe, DOSHWA in those days, the inspector spied a can of 2 pack and we got lectured on the use of PPE, which we had. He didn't care that the exhaust blower directed the fumes directly at the workshop next to us. He said he only cared about the workers in my shop. I didn't like that so installed water scrubbers onto the exhaust.

Originally Posted by DoctorWu

All very tempting to go with an epoxy enamel and a brush.
However these thoughts over painting only started once I had dismantled the 2nd lathe to get it into the workshop. It's in pieces so why stop there, I thought? I am an obsessive yet am smart enough to understand the meaning of the appropriate use of energy and materials and in this case as it is for me a once in a lifetime job, it makes sense to go with the more involved process.

With second thoughts, some hindsight and in the interests of safety I've decided now to go with 2 pack paint, BUT with a sponge roller and brush. The amount of flat areas are quite small.
My decision regarding 2 pack use is that in the past whenever I've used for instance, epoxy enamel, it sets up too quickly so that any brush marks don't 'lay down'.
So it is ok to go over an enamel if it is properly prepared with 2 pack paint? I think most likely an epoxy.

Originally Posted by DoctorWu

With second thoughts, some hindsight and in the interests of safety I've decided now to go with 2 pack paint, BUT with a sponge roller and brush. The amount of flat areas are quite small.
My decision regarding 2 pack use is that in the past whenever I've used for instance, epoxy enamel, it sets up too quickly so that any brush marks don't 'lay down'.
So it is ok to go over an enamel if it is properly prepared with 2 pack paint? I think most likely an epoxy.

Best to read the data sheet for your chosen paint. For example, the Northane 2 pack poly I'm using says this in the data sheet:

Northane should only be applied over sound surfaces. Where the previous coating is unknown, apply some Acetone on a rag to see if the old paint softens. If it does, remove the paint before continuing.

For what it's worth, Northane with skilled application (not me, mostly!) can be put on with fairly minimal brush marks, and actually noticeably self levels for about 2 days. If you get it right, you get a texture that looks like sprayed with a bit of light orange peel effect. Not cheap stuff, but supposedly chemical and abrasion resistant. Time will tell.