The Home Machinist!

I know there are several people like me here who like to refurb old machines. What are you guys using for respraying or painting the machines? The idea of using a brush does not appeal to me because of the time and effort prep makes it's frustrating to ruin the finish with a brush.

I don't repair large machines and for the most part the machines are in small manageable pieces before painting. I was thinking of getting a mini-spray gun like this:

http://www.spraygunworld.com/products/A ... rCase.html

and buying the larger cup in case I have larger pieces to spray in the future. Can anyone comment on this? I am past the point of using spray cans and brushes and don't mind investing in a decent set-up for small projects. There is a possibility I will get it with a pressure pot system as well to enable me to spray up underneath items on the odd occasion when the need calls for it. I already have the compressor,regulator and water seperator and will make an air dryer that uses dessicant if I pull the trigger on the kit.

Thanks for any help.

Paul.

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Speak with the circus owner instead of arguing with the monkeys.

Seems a little pricey for occasional home use. The one I have for auto touch ups and outboard motors was under $100, and it has a steel cup too. (Only two tips though, and no pretty molded case.) But that one does look like a quality piece with a number of fine adjustments that a pro would look for. I also have a 1 qt gun for larger jobs like an entire car, but it's amazing how much area you can cover with 3 or 4 oz of paint. So for what you are doing, I wouldn't bother with the 12 oz cup, maybe the 4 oz SS one would be best. That is an HVLP gun, so there's a lot less paint wastage through overspray. I'd get tips in the range of 1.0 to 1.5. 1 or 1.2 is usually good for automotive paints but 1.5 might be better if you start spraying an epoxy paint.

The prep will be the same whether you are brushing or spraying.

Differences I see are:
Spraying - have to set up a clean all the spraying equipment. You also need to mask.
Brushing - you would have to clean the brush, and since it would be oil-based paint, you would need to use solvent (which is a pain), but I would just throw the brush away and consider it a cost of painting.

You might have brush marks, but a good paint will level out. Several people have gotten good finishes using brushes.

Do some searching on practicalmachinist.com on painting and you will see some good recommendations on paint and techniques.

This was painted with a brush and Tractor Supply enamel:

(note: that's NOT mine)

Steve

I know it sound silly but the tools I use least I tend to try spend a little more money on. I want them to work when I pick them up and if for any reason they stop working, I know parts will be available. The sprayer would also be used for wood projects too so it's not like it will only see use when I am refurbing a machine (which does happen semi regularly anyway).

SteveM: I realize the prep will be the same, but given the amount of prep required for machines that have many components, I want the best finish possible to justify the effort and time spent. I have used many different types of paints, both in cans and with brushes and so far the can gives me the best finish. Given the price of quality paint in a spray tin here in Norway, I figured importing one of these would pay itself off in 3 projects that I would normally have used a spray can. To give you an example, a tin of Hammerite hammer effect in silver costs 26 USD in Norway.

Torch: Thanks for the advice on the cup size. I was not sure which size would be most suitable for big projects (big as in a milling machine sized project for example). I do make furniture so if I was to spray clear on a table, I hope that a 4 oz cup will be enough.

Paul.

_________________
Speak with the circus owner instead of arguing with the monkeys.

It depends on the size of the table

Seriously, I think you should easily get a coat at a time on a table top with a 4 oz cup from a HVLP (High Volume Low Pressure) gun. They waste much less paint than a traditional gun. I can put a layer on a car hood. And I'm talking Buick Roadmaster sized hood, not some little Ford Prefect cap.

For multi-part paints like automotive finishes or industrial epoxy paint you don't want to mix more than you really need anyway. You can always mix more and refill the gun between coats. Or paint different parts on different days as the project progresses.

One final advantage of a small gun/cup: it takes less solvent to clean the damn thing afterwards. And make sure you clean it, then clean it again then repeat the process if you ever want to use the gun again!

I hear ya. I have a HPLV airless sprayer I use for painting houses and barns and that thing needs some serious cleaning and maintenance practices to keep it in working order.

I have a milling machine to refurb over the next 6 months so I will add the sprayer to my "nice to have" list.

Paul.

_________________
Speak with the circus owner instead of arguing with the monkeys.

OUCH!

It's about $8 here.

Steve

Hi There,

I have sprayed many machines (mostly lathes) and, like the
others have said, it's all in the prep. I still use a brush sometimes
and I like using a brush for some of the more difficult parts to mask.
(like the spokes of a handwheel). I have a couple good spray guns
(DeVilbiss) and I clean them religiously (three times after each use).
I use a bottom cup siphon feed type gun.

Occasionally I would do the whole machine with a brush. A good
oil-base enamel will flow-out with minimal to no brush marks. laying
the paint too heavy and getting drips is the biggest problem I have
with brushing. Whether using a brush or spraying, thinning and the
ambient temperature plus humidity all play a part and have to be taken
into consideration in order to get good results. In spraying, you need
a clean and ample air supply.

Another consideration is the type of paint to be used. A lot of people
like the catalyst/polyurethane paints (like Sherwinn Williams Polane).
This type of paint is extremely durable but will screw-up your gun if
you don't clean it out right after use (it will harden inside the gun).

Good Luck!
-Blue Chips-
Webb

I do not know much about paints, but read somewhere that a good custom auto paint shop may be able to fill a rattle can for you for a relatively decent price.

_________________
Standards are so important that everyone must have their own...
Logan 10x24 Lathe, RF-30 Mill, 20 Ton Press
Disclaimer: I'm just a guy with a few machines...

I did the adapter for my Bridgeport head with a brush and it came out nice. Used Rustoleum gray.

The difference between machines and cars is that the machines don't start out as smooth. You don't need a mirror finish for a machine to look good. On a car, it's important.

One day, my family pulled into a restaurant parking lot and we saw a black Mercedes 300sl gullwing in the parking lot. We walked over to take a closer look and it had brush marks all over - someone's idea of a budget paint job.

Eastwood sells a refillable spray can:
http://www.eastwood.com/media/catalog/p ... p32621.jpg


Probably more suited to doing smaller tasks.

Steve

I just use the import guns from HF. I'm not doing show cars.
Use only HVLP, especially in the full-size guns.
the touchup guns are OK in a standard-type gun.

I picked up a cute touchup gun last night at HF for $12.99

http://www.harborfreight.com/air-tools/ ... 92126.html

I use a devilbis hvlp. Like you, I hate to do all the prep and then end up with something that looks like a brush job. I admit I'm not much good with a brush. Cleaning a gun isn't a big deal after you've done it a few times. Like others have said, it is imperative to keep the gun clean. On the negative side....if your painting a milling machine and you don't take the time to bondo it like they did when they first painted it, you might as well brush it. The grinding marks in the castings are something no amount of paint will cover up. I just finished a bridgeport and it looks great until you get close enough to see all the imperfections in the castings. The other problem I have is cure time. I have a logan lathe thats been sitting curing for about a week now. If I started assembling it tomorrow I know I would scuff the paint. I don't use urethane because I don't want the waste disposal problem. Autobody toolmart usually has good prices on spray equipment. Good Luck, Chuck