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!
The Monroe Mark II Mailbox
For Christmas, Michelle asked me to build her a new mailbox since the last one that I had built was in her opinion too small i.e. it was too hard to get the mail and newspapers out of it. In my opinion it was fine, we just get too much mail, but since she is a good wife and doesn’t place much demand on me, I decided to build a new and better mailbox.
The Monroe Mark II Mailbox is two inches wider, two inches longer and two inches taller with a redesigned easy in, easy out door. It is still constructed of .25″ thick steel and will be mounted using four 3/8″ grade eight bolts, on the existing and proven mounting post. The plates were cut from a larger sheet using a computer controlled plasma cutter and MIG welded together using .035 steel wire. Before welding the roof on, I sprayed epoxy primer on the inside of the box to prevent rust.
Unfortunately it has been pretty cold this winter I was having problems with the igniter in my shop furnace, so I was not able to get the shop heated up to more than 62 – 65 F which was not really warm enough to allow the primer to cure properly. Even though I reduced the primer with a cool reducer – rated to 60 F, it really needed to be much warmer for it to set up properly. Based upon this experience, and the fact that the trailer is still buried under 8″ of snow – I may put off sand blasting and primering the ’56 until it gets warm enough to where I can easily hold the paint booth to at least 70 F.
After welding the top on the box, I primered it with an oil based primer that had a low temp rating of 50 F, it is curing better than the epoxy, but it’s going slow. Did I say it’s been cold this winter? We have been having night time lows around 1-2 F for the past couple of weeks! Anyway, I should be able to spray the color coat sometime today or tomorrow and hopefully it will replace the Mark I box this weekend.
I guess I should have taken a few photos of the box during it’s construction – but I was lazy – I will do some photos when I install it!
