Repainting cast iron/turbine HVLP

[ebarker9]

I'm in the midst of what has turned out to be a partial restoration of a Walker Turner 14" band saw. I decided that I wanted to get as close to the original color as possible which was suggested to be "Benjamin Moore 1575" in the direct to metal alkyd. I'm attempting to spray this using one of the Rockler turbine HVLP guns although I realize I might be asking too much of the gun. I'm thinning, a lot, with Naptha, then running through a filter into the gun. It's been very challenging getting a consistent mix of the paint and thinner. I'm spraying using the 1.0mm tip. My issue is mainly that I'm getting very uneven results. I can get a nice, even flow just spraying the thinner but with the paint mix it spatters quite a bit. Fortunately the paint has done a good job of self leveling but it's still not quite the finish I'd hoped for. Before attempting another coat I figured I'd see if anyone out there has suggestions for improvement with my setup. As much as it would be nice to have a regular HVLP setup I don't really want to take up the space or spend the money on a large enough air compressor. Here are a few pictures of the results for reference:

This was my first attempt where I think I had some surface contamination. I stripped that coat after a lot of cursing and tried again.



The latest:

[Kansas City Fireslayer]

That's going to be a great saw when put back together. I'm sure you're doing new bearings as well? Now would be the time. If it were me, I'd forget the HVLP and use a foam roller with a tad bit of thinner. The cast surface is rough and porous so I don't think you'll loose much, if anything, in regards to finish quality. The foam roller may even give you a smoother surface being it will push extra paint do into the crevices. Spraying will not always fill they voids. The paint you're using should flow out pretty well if it's oil based. For now, you could sand the paint back to even things out and give the foam roller a go. You may need some small brushes for the tight areas. In the end, it will still look good and much better than it was before the new paint job.

[ebarker9]

Thanks, I may wind up doing that. The spray looks good on the smoother surfaces (the non cast iron parts) but I don't think it is any better than a roller on the cast surfaces.

I am replacing all of the bearings, tires, etc. Should be a brand new machine when it's done.

[Kansas City Fireslayer]

The crack in one of the wheel housings could also be filled with Bondo and sanded smooth. I'd consider drilling a very small hole at the end of the crack to hopefully stop it right there. You could fill the hole as well. Now would be the time to do it and it wouldn't take long.

[ebarker9]

Kansas City Fireslayer said:

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The crack in one of the wheel housings could also be filled with Bondo and sanded smooth. I'd consider drilling a very small hole at the end of the crack to hopefully stop it right there. You could fill the hole as well. Now would be the time to do it and it wouldn't take long.

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I'm worried about the slippery slope with Bondo. You start out filling only the large imperfections and before you know it the entire thing is covered and you've spent 3 days sanding

Actually, from the other side of the casting you can just make out that crack going all the way through so I don't think there's still the option to drill the hole. I can't see there being any significant stress on that part of the casting so I'm probably just going to live with it and if it progresses I'll attempt to get it welded.

[jteneyck]

If it's sputtering you need a larger orifice and/or more thinner. You might want to try mineral spirits instead of Naptha, assuming it's compatible with that paint, as it will evaporate more slowly and allow the paint more time to flow out before setting up.

But I agree with KCFS, rolling on the paint might be easier and result in a better finish for you.

John