I've noticed on our nice new machine tools that when the paint gets chipped it appears to be very thick. There also appears to be a thick white coating under the paint. What kind of process is typically used to finish a machine tool with the characteristics that I described?
Bondo
Regards
Daveb
DaveB wrote in news: snipped-for-privacy@news.dslextreme.com:
Plus primer and two part epoxy paint.
Dan
Industrial bondo...fill and paint.
Gunner
Every normal man must be tempted, at times, to spit on his hands, hoist the black flag, and begin slitting throats. H. L. Mencken
On older machines, sometimes tar (or something very tar-like) was used where the bondo is on modern machines, based on personal experience.
Let me get some info from Al Babin... and I'll get back to you........
LMAO, Ron
What do they do... thin the bondo and spray it on? I can't imagine them doing it by hand.
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| >>I've noticed on our nice new machine tools that when the | >>paint gets chipped it appears to be very thick. There also | >>appears to be a thick white coating under the paint. | >>What kind of process is typically used to finish a machine | >>tool with the characteristics that I described? | >
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| > Industrial bondo...fill and paint. | >
| > Gunner | >
| | What do they do... thin the bondo and spray it on? I can't imagine | them doing it by hand.
Slap, spooge and shove out into place. Trim and file. Repeat. Thick paint to hide the file marks.
Just about anyone that works castings does it. If not Bondo, then other similar materials.
Thin the bondo, and put it on by hand. At least in the old days. Shrug..its not all that hard to cover up a casting with filler and give it a quick smoothing with sand paper, then paint with something nice and thick.
Gunner
Every normal man must be tempted, at times, to spit on his hands, hoist the black flag, and begin slitting throats. H. L. Mencken
As you've described them, it appears your tools are Pacific rim look-alikes of domestic tools.
A really good tool will have the castings "hooked" smooth all over. Then a simple prime coat and enamel works fine.
The oriental low-cost tools are typically left with the castings completely rough. They are then painted in a THICK coat of white or red lead filler, sanded _somewhat_ smooth, then enameled.
LLoyd
Sometimes heavy 'white lead' was used on older machines too ... about like the 'settlings' at the bottom of the cans of old lead paint. If you suspect this, use of a lead paint 'test kit' would be in order before doing a lot of sanding or grinding. While lead is toxic, it's not much of a problem until you either heat it, or turn it to dust.
Dan Mitchell ============
You say decent machines DON'T use 'bondo' like glazing under the paint?
That's odd ... the Bridgeport is genrally regarded as a decent mill, and they have LOTS of 'bondo' all over the non-machined casting surfaces ... up to 1/4 thick in places. So do most other USA made machines I've ever seen. So too do most better grade foreign machines. It's the norm on most castings-based machinery.
Dan Mitchell ============
I won't argue the point, since the newest machine I own was built in 1961. But it wasn't true for most quality tools (I have seen) of that and past eras. My F.E. Reed lathe hasn't got a smidge of filler on it anywhere, and my Cincinattee #2 mill has only a few spots on the lower base. I stripped and re-finished them, so that's not guess.
Perhaps in an effort for "increased productivity" modern toolmakers are taking cosmetic shortcuts they didn't before. Still, wouldn't you be a bit put off by finding a 1/4" of filler on something that's supposedly structural?
LLoyd
Not if it was obviously there for cosmetic reasons, and the actual amount of metal underneath was adequate to the job.
Of course I tend to care far more about function than form -- my truck comes in 4 shades of "forest green" but the engine only has 30000 miles on a very high-end rebuild, I build prototype circuits with ugly-as-sin construction on bare copper-clad board because it works well, I previous rode bicycle had bare-metal spots on the top tube because my rain pants kept the rust rubbed off, etc.
Indeed. Having stripped more than a few Hardinge lathes...the "bondo" layer can be thick indeed on them.
Gunner
Every normal man must be tempted, at times, to spit on his hands, hoist the black flag, and begin slitting throats. H. L. Mencken
We have Mazak's, Warner & Swasey's, Mori Seiki's, and some older stuff and it seems like it is all finished about the same. I suppose I'm wrong but I know I've seen the thick finish on some of them.
Machine tools manufactured during WWII generally had tags by the "War Finishes Board". These tags indicated that the machines were well made but due to labor shortages the extra effort required to smooth the castings and make the machines "pretty" was not available. All nice machne tools are heavily glazed and the older machines have some kind of a clay based glaze while I' m sure newer ones are using catalized polyester resin. Never sandblast a cast machine, unless you have to, as you will open up more horrible gaps and visually distressing openings then you can imagine. I have a lovely LeBlond lathe that a former owner sand blasted only to find holes straight through the base castings. I just had a ex-Navy Famco #6 arbor press stripped and there are about two or three pounds of filler now reqired to close up the rough spots. The sandblasting was required as the machine had 15 coats of paint with rust under the first one. If you ever want to see a beautiful machine finsh, check out some of the older Italian machines. They use the same materials and techniques used on the hand buillt Ferraris and Maseratis. Actually most of the car manufacturers over there made machine tools as well, but not Ferrari. Leigh@MarMachine
My dad used to do bodywork on exotic cars. He had one Italian hand-built car in that was basically a 1/8 inch skin of bondo over sheetmetal that was as rough as a cob -- and that was from the factory.
Don't know about american iron, but I've stripped a few old swiss high-class machines ; the castings were filed somewhat smooth, coated with red lead primer, thick whitish filler, and then a top coat. the only exception I know of was Mikron who apparently left their castings completely untreated, with maybe only a transparent top coat (
Hans
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