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Machine Tool Paint: Cheaper, more readily available alternative to Polane, Imron?

TimNJ

Plastic
Joined
Aug 21, 2021
Hi all,

I am in the middle of restoring an old Walker Turner 900 series drill press and wish to repaint it. After reading through many suggestions on Practical Machinist forums (and others), the general consensus was that paints like Sherwin Williams Polane B or DuPont Imron have the greatest durability and chemical resistance. Of course, they are also quite expensive, and availability and color selection appears to be limited.

I am considering a few options, but I know almost nothing about paint, so I do not know the benefits of each type.

Dupli-Color Engine Enamel with Ceramic (Spray): Engine Enamel with Ceramic™ – Duplicolor


  • $10/can
  • Advertised chemical/oil resistance, I believe "with Ceramic" implies an epoxy-ceramic resin
  • Advertised as "This durable formula resists temperatures up to 500°F intermittently and produces a superior finish that will not blister, flake, crack or peel."
  • Limited color selection, would probably pick gray


BEHR Urethane Alkyd (Brush): BEHR INTERIOR/EXTERIOR URETHANE ALKYD SEMI-GLOSS ENAMEL NO. 3900


  • $35/gallon
  • Urethane formulation is possibly more durable (chip resistant) than epoxy-ceramic resin (above?
  • Typical application is trim/molding/cabinetry
  • Large color selection, can choose "Hunt Club Green" or similar to match original WT paint

Sherwin-Williams Pro Industrial Urethane Alkyd Enamel (Brush): Pro Industrial™ Urethane Alkyd Enamel - Sherwin-Williams


  • $120/gallon
  • Seems similar to BEHR brand from name/advertising perspective, but 4x the price..
  • Large color selection

Am I in the right ballpark? Does a urethane base make sense? Any tips are appreciated.

Thanks,
-Tim
 

Domodude17

Aluminum
Joined
Aug 14, 2017
Hi all,

I am in the middle of restoring an old Walker Turner 900 series drill press and wish to repaint it. After reading through many suggestions on Practical Machinist forums (and others), the general consensus was that paints like Sherwin Williams Polane B or DuPont Imron have the greatest durability and chemical resistance. Of course, they are also quite expensive, and availability and color selection appears to be limited.

I am considering a few options, but I know almost nothing about paint, so I do not know the benefits of each type.

Dupli-Color Engine Enamel with Ceramic (Spray): Engine Enamel with Ceramic™ – Duplicolor


  • $10/can
  • Advertised chemical/oil resistance, I believe "with Ceramic" implies an epoxy-ceramic resin
  • Advertised as "This durable formula resists temperatures up to 500°F intermittently and produces a superior finish that will not blister, flake, crack or peel."
  • Limited color selection, would probably pick gray


BEHR Urethane Alkyd (Brush): BEHR INTERIOR/EXTERIOR URETHANE ALKYD SEMI-GLOSS ENAMEL NO. 3900


  • $35/gallon
  • Urethane formulation is possibly more durable (chip resistant) than epoxy-ceramic resin (above?
  • Typical application is trim/molding/cabinetry
  • Large color selection, can choose "Hunt Club Green" or similar to match original WT paint

Sherwin-Williams Pro Industrial Urethane Alkyd Enamel (Brush): Pro Industrial™ Urethane Alkyd Enamel - Sherwin-Williams


  • $120/gallon
  • Seems similar to BEHR brand from name/advertising perspective, but 4x the price..
  • Large color selection

Am I in the right ballpark? Does a urethane base make sense? Any tips are appreciated.

Thanks,
-Tim

On a previous south bend lathe, I used what was described as "implement paint" from Tractor Supply, it was an oil based enamel if I remember correctly. You can add a hardener to it which improves some of it's attributes. it's worked very well, the only spots i've had issues with are ones that probably just didn't get properly prepped. Didn't even use a primer and it's been fine. Left a hard, glossy coat. I don't remember how much it cost, but it was available in quart size cans which keep the cost down. The downside is it's really only made in tractor colors, so yellow, green, red, a basic light gray, etc. I did some mixing to end up with a classic looking SB gray.

I'm working on a Clausing Colchester right now, and I went with "Sher Kem" from Sherwin Williams. I think it's the same sort of thing, cost $60/gal. Used a hardener. Was able to get a color match to replicate the original paint.
 

TimNJ

Plastic
Joined
Aug 21, 2021
On a previous south bend lathe, I used what was described as "implement paint" from Tractor Supply, it was an oil based enamel if I remember correctly. You can add a hardener to it which improves some of it's attributes. it's worked very well, the only spots i've had issues with are ones that probably just didn't get properly prepped. Didn't even use a primer and it's been fine. Left a hard, glossy coat. I don't remember how much it cost, but it was available in quart size cans which keep the cost down. The downside is it's really only made in tractor colors, so yellow, green, red, a basic light gray, etc. I did some mixing to end up with a classic looking SB gray.

I'm working on a Clausing Colchester right now, and I went with "Sher Kem" from Sherwin Williams. I think it's the same sort of thing, cost $60/gal. Used a hardener. Was able to get a color match to replicate the original paint.

Thanks much. What is an example of a compatible hardener? Use the ratio prescribed on the hardener can?

I actually don't mind the "Massey Ferguson Gray" instead of the Walker Turner green, but it sure would be nice to match the original. That's why I am trying to understand if there is something special about this kind of inexpensive "farm/implement" enamels vs something like the BEHR from Home Depot.

I appreciate the input.
 

Destroyer125

Plastic
Joined
Aug 11, 2021
I'm restoring an old 1950s Clausing and using Rustoleum Professional Smoke Gray with Majic Enamel Hardener and Japan dryer; spraying it from a HVLP. The results are way better than rattle can and the finish is pretty good for a cheap alternative. Using Spraymax 2k Epoxy Primer underneath to get a good bond to the base metal.
 

TimNJ

Plastic
Joined
Aug 21, 2021
Thank you for your input! What is the ratio for the hardener in the Rustoleum? And what is the process for using Japan drier?
 

Destroyer125

Plastic
Joined
Aug 11, 2021
Mixing from the 1 gallon can of Rustoleum Pro. 4 Paint : 3 Acetone : 1 Hardener : Splash of Japan Dryer. The Japan dryer isn't required for the mix but it does boost cure time. Applying 1 coat per hour in 70-90 degree weather. Your going to get a rock hard and durable finish with this recipe thats hard to the touch in 24 hrs.
 

TimNJ

Plastic
Joined
Aug 21, 2021
Mixing from the 1 gallon can of Rustoleum Pro. 4 Paint : 3 Acetone : 1 Hardener : Splash of Japan Dryer. The Japan dryer isn't required for the mix but it does boost cure time. Applying 1 coat per hour in 70-90 degree weather. Your going to get a rock hard and durable finish with this recipe thats hard to the touch in 24 hrs.

Thank you much. I am still somewhat interested in matching the original green paint. I am curious if I could adopt a similar recipe/method but using the BEHR Alykd Urethane Enamel paint. Price is good and I can get any color. Perhaps the hardener should be a “urethane hardener” instead? As I mentioned, my understanding of paint and paint chemistry is basically zero.

I think I will try on a scrap piece of iron first, see if I can do a similar ratio with a paint different than the one you reference, and see how it works out. If anyone has any recommendations, I’d love to hear them.

If it doesn’t work out, I am happy to go with Rustoleum Smoke Gray. Thanks.
 

Domodude17

Aluminum
Joined
Aug 14, 2017
Thanks much. What is an example of a compatible hardener? Use the ratio prescribed on the hardener can?

I actually don't mind the "Massey Ferguson Gray" instead of the Walker Turner green, but it sure would be nice to match the original. That's why I am trying to understand if there is something special about this kind of inexpensive "farm/implement" enamels vs something like the BEHR from Home Depot.

I appreciate the input.

The store had hardener right next to the paints and I think it was the same brand, so that's what I went with and it worked out fine. I believe the ratio was on the can of hardener. Something like 1:8, 1:10, or 1:12.

I think the main difference is that they're probably selling millions of the cans of implement branded paint. On my south bend I spent a significant amount of time mixing different paint ratios with eye droppers to try to get a color I was satisfied with. Very critical work, you know :D
 

TimNJ

Plastic
Joined
Aug 21, 2021
The store had hardener right next to the paints and I think it was the same brand, so that's what I went with and it worked out fine. I believe the ratio was on the can of hardener. Something like 1:8, 1:10, or 1:12.

I think the main difference is that they're probably selling millions of the cans of implement branded paint. On my south bend I spent a significant amount of time mixing different paint ratios with eye droppers to try to get a color I was satisfied with. Very critical work, you know :D

Thank you. Given that it's basically impossible for someone on the internet to predict how "Hardener X" will work with "Paint Y", I guess best option is to run some tests. I am curious whether a glass-like finish really makes sense compared to something a little more plastic. I would imagine glass finish will chip/flake more easily, while a more plastic finish is more likely to dent/deform. On the other hand, glass finish will probably be generally more resilient (up until a point), and beyond that point it will probably make an uglier wound.

Seems most hardeners I've seen are 1:16 or 1:12 or so. I suppose if I am really worried about being "too hard", just use less hardener like 1:24, 1:32, etc. ;)
 

gustafson

Diamond
Joined
Sep 4, 2002
Location
People's Republic
Automotive acrylic urethane has far fewer of the nasties of imron/polane and is pretty tough

Auto paint store will use the camera to match your original paint

I think the biggest problem is 50 years of embedded oil ruining adhesion
 

ballen

Titanium
Joined
Sep 25, 2011
Location
Garbsen, Germany
I painted my Deckel FP2 a year ago (a couple of photos below) so have some comments about this.

First, regarding paint:
There is a lot of work involved in painting including scraping off bad paint, getting oil out of the pores, sanding, derusting, priming and filling, and more priming and filling. Given that, it's a false economy to scrimp on the paint. Pay what's needed to get the paint that will work best.

Second, regarding curing times:
I sprayed multiple layers of a two-component polyurethane (MIPA PU 200-90 with PU 900-25 hardener). Being a 2-component paint, it hardens by curing, not by evaporation, so one might think that a day or two is enough to reach full hardness. That would be the case if I was able to bake the paint in an oven at 60C = 140F. But in my case, the curing takes place at room temperature, and it takes a few *months* before it reaches the final hardness, which is close to glass like, but still very tough. Personally that's the surface that I think is the easiest to maintain and which offers the most protection.

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TimNJ

Plastic
Joined
Aug 21, 2021
Thanks everyone for the good discussion.

Well, I took a bit of a chance and went with the BEHR Urethane Alkyd Enamel (Semi-Gloss) from Home Depot. Only $17/quart. I picked the color "North Woods", seems close to the original Walker Turner green, but perhaps a touch more green.

Prep process was as follows:

Degrease -> Jasco paint stripper -> Degrease -> Wire wheel -> Degrease -> Wire wheel -> Isopropyl alcohol... Seemingly, no amount of degreasing will truly get rid of all of the embedded crud. But, I had to stop somewhere.

I used BEHR No. 435 Metal Primer. The adhesion was great, but was not happy with the tackiness/stickiness that remained some two days later, even though the can says "ready for top coat in 1 hour". Don't think I've tried to brush on a metal primer before so I figured "well, this is just the way it is". Photos on Home Depot's website seem to show a brushed-on appearance consistent with what my primed surface looked like. Still wish it had dried/cured hard, for my own sanity. Time will tell if this is really an issue or not.

For the top coat, I applied two coats with an ultra soft Purdy Syntox brush. The first coat I applied quite thin, about 50% coverage, lots of primer still visible. I waited two days between coats. After two days, the green top coat was still far away from passing the fingernail test. I applied a few hours of elevated heat and airflow prior to the second coat, though I don't think it did very much.

The second coat was applied rather thick, as applying it too thin appears to impede the self-leveling nature of the paint (i.e. too many brush strokes). Second coat was applied two days ago. I've now applied about 10 hours of elevated heat and airflow and the hardness appears to be improving, but it is very slow, and still not close to passing the fingernail test. BEHR states 7 day cure time at 77°F, although a BEHR representative answered this question on Facebook (of all places) and said 30 days.

In any case, it is foolish to think the paint would reach full hardness in just two days, but it certainly is still a little unnerving. It also makes me question the practicality of such a paint in the first place.

Anyway, here's my cobbled together "curing oven". Thought about doing a more proper job with a temperature controlled relay (i.e. Finder 7T series) to control the space heaters (as to actually regulate the temperature, and not dump so much wasted heat into the surrounding room). For my purposes, I just set up the box such that it equilibrates at about 120°F. Seems good enough for me.

DSCF7230.jpg
 

TimNJ

Plastic
Joined
Aug 21, 2021
After two months of cure time, I am not too happy with the durability of the BEHR urethane alkyd enamel paint. The initial tackiness went away after about 2-3 weeks, and it cured to a seemingly hard finish. But even after two months, it still fails a fingernail test with modest to heavy pressure applied. Light color marks are left where my fingernail dragged across the surface. With light pressure, fingernail skates over the surface, which is good, but beyond that, not great.

I tried wiping down the painting surface with rubbing alcohol (91%) and the paint came up quite easily onto the cloth. This is again, after two months of cure. I like to use IPA to clean off oil, grime, dirt, etc., so this was disappointing to me.

I won't discount user error completely, but my impression is that it is just not tough enough.

I am considering spraying a (known) hard clear-coat on top of this, but not sure if that's a great idea.

I will most likely sand down the top-coat, and re-paint with Rustoleum Farm & Implement paint sometime in the spring when it is warmer, and the conditions are better for painting.
 

mmarquette

Cast Iron
Joined
Dec 20, 2016
I used PPG AUE with hardener for lots of equipment . If coated with a clear of the same with hardener was quite tough to me . Gave color a layer of protection
 

HappyWyo

Aluminum
Joined
Nov 30, 2019
We use rustoleum smoke grey straight from the can, but our machines are work machines. Most important thing to remember unless you use oil based the paint won't stick to any residual oil left behind, and it won't get hard either.
 

dalmatiangirl61

Titanium
Joined
Jan 31, 2011
Location
BFE Nevada/San Marcos Tx
For something as small as a drill press, I'd rattle can it. The black epoxy is durable after its cured or baked, or silver hammertone is nice too. But since you prefer green........... If you want more color choices there is rustolem oil base paint, pretty sure your choices are white, black, grey, and red.
 

wheels17

Stainless
Joined
May 10, 2012
Location
Pittsford, NY
TimNJ, Isopropyl alcohol seems to be a tough solvent on machine paint. I have a South Bend(1979) lathe that was repainted at some point. I found that IPA was the best solvent to get dried Cool Tool 2 goo off the lathe, until I noticed that it was taking the paint off as well. I've had the lathe for 10 years, and it looked to have been repainted long time before I bought it. It would take off both the repaint and original paint.
 








 
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