The Monroe Mark II Mailbox
I finally replaced the old Mark I Mailbox with the new and improved larger Mark II version.
The paint job on it did not go all that well. When I tried to prime it with automotive epoxy it was only about 65F in the shop and the epoxy did not cure fully even though the reducer I used was supposed to be good to 60F – so I stripped it off and primed it with an oil based primer (Rustoleum) that was rated to 50F.
Unfortunately the primer did not have any kind of tech sheet with it – and the instructions on the can assumed that you were going to use a brush or roller to apply it. So I figured that I would thin it 10% with paint thinner – not a good idea too thin and several major saqs resulted.
I wet sanded the primer with 180 grit to knock down the sags and then painted it with a oil based top coat, but didn’t thin it. It layed out okay, but the coverage seemed inconsistent, but no orange peel, dry spots or runs! But I could still see where the primer had sagged – I should have spent more time sanding…
Okay, I wet sanded the top coat with 360 grit to even everything out. Shot it again with the top coat, but this time I tried some different settings of the HF 43430 HVLP gun. I kept the air pressure the same but narrowed the pattern and cut back on the material adjustment. When I started to spray the box, I would get a nice pattern, then it would act like it was running out of material, then start spraying okay again. Things were looking pretty ugly by the time I had finished one side. In addition to the weird pattern, I started getting all manner of small particles in the paint. I decided that the best course of action would be to get the paint thinner and a clean rag and wipe off all the new paint. Once that was done, I ran several tests to see if I could determine what was I doing wrong. I tried spraying a piece of cardboard with several different settings and I still kept having the the running out of material problem. I found that I even had the problem when I was spraying only thinner or solvent!
The HF 43430 HVLP comes with a small strainer that fits between the paint cup and the body of the gun. It was the only thing that I could think of that could be restricting the material flow, so I removed it and loaded the gun with thinner and it sprayed great! The more that I looked at the little strainer, the more it seemed that the instructions that came with the gun had you installing it upside down. I took the gun apart and cleaned it once again, then put the strainer in upside down according to the instructions and it worked great, exactly the same as when I tried it without the strainer.
With the paint strainer installed upside down, I filled the gun with double filtered top coat, opened the pattern up, increased the material flow and once again sprayed the box. The material flowed well and it held a good pattern and the material layed out wet and slick with no sags or runs, the bad news was that the surface was covered with small particles. I emptied the paint cup and disassembled the gun and placed the parts, including the body, in a clean container and filled it with lacquer thinner. I let the parts soak for about an hour then removed them and dried them off. When I went to dump the used lacquer thinner I noticed the bottom of the container was filled with what looked like fine metal particles. I then closely inspected the body of the gun and found that the purple ’anodize’ coating on the inside of the gun had been flaking off.
After the paint had dried, I decided that the paint finish was ‘Good Enough’ for a mail box and hauled it out to the curb and replaced the old box with the new and larger one. Michelle was quite happy with the result, and I am thinking that I might need to bite the bullet and buy a better quality gun… more to follow!
