Monday, June 17, 2019

Blocking 2K Primer and a Dead Compressor | Roundtail Restoration

A bit behind again, so this will be a two-fer. Starting off, once you spray, you must block! To the video!


At the end of the last update, I got three coats of 2K build primer on the inside of the bonnet and on the sills and rear of the. With the next visit, it was time to start blocking it all out.

Sounds like a broken record, huh? But, to provide a bit more information, I started with 150-grit blocking, then moved to 220-grit, and then on to 320-grit. I'm doing this all by hand for now as the use of an orbital sander scares me a bit...afraid I'll cut in too deep and mess something up.

As I stated with the inside of the bonnet, I am trying to flatten it out to make up for the fact that I didn't take it to bare metal except in spots that had some rust. I wanted to make sure it was all surface stuff, which is was, but that resulted in a difference in height between the paint and the bare metal. Not something I thought about at the time, but once I had started the path back to red, the subtle height difference was quite apparent. This was my second round of 3 coats of build primer and I was hoping that would do it.

The build primer is made to fill in the subtle lows and the rest of it, on the higher spots, gets sanded into dust and brushed to the floor. It's the last step in make sure your panel is straight. It's not magical though, so if you didn't get it the panel near 100% with either metal work or filler, the build primer is not going to save you! There are other options out there that are more aggressive, you could say, like Slick Sand or Feather Fill (both by Evercoat; I'm sure there are lots of options out there). These are essentially sprayable filler material. I didn't really look into this as an option. No real reason and it may have been a better choice for me in the long run, but I really can't say either way.

Again, I start with 150-grit blocking, using a 4-inch or 9-inch block depending on the panel. The inside of the bonnet is tricky because the curves are concave, which makes it harder to block. But, it is the inside of the bonnet, so I'm not so concerned about it being perfect. I'm not going to cheat and put down Raptor Liner, but I've had that discussion with myself more than once!

Once the 150-grit is done, it's on to 220-grit, also with a 4- or 9-inch block.

Following blocking through 220-grit.

The desire is that as you move up in grits (e.g., 150 to 220 to 320) you would like to get a longer block, going all the way out to 18" if possible (which is the longest block that I have. They make a 24-inch and even a 30-inch one as well, but I figured that was overkill for Dorothy's small stature). The longer the block, all things being equal, the straighter the panel when your done. But, the inside being convex, I was mainly locked into using the 4-inch or 9-inch block. In some spots, I used a 4-inch soft block that allowed me to follow the contour and even just my bare hand, though lightly so as not to introduce unevenness.

Trouble areas near the wheel arches. More blocking.

Same concerns, but other side.

The garage mate was headed over for a rare visit while I was there and I was going to have him help me flip the bonnet so I could start the "good" side. We got to talking about the garage layout and the amount of stuff that we had both accumulated over the preceding several years and we decided to go to town, gut the place, clean it up quite a bit, and reorganize and restow everything. The sucked up the rest of the day, but the results were worth it. We got rid of a lot of junk and otherwise made a more efficient use of the 20' x 40' space.

Tool box is on other side now and much more accessible.

New shelving unit and a better use of space (like the drill press where it can be always plugged in).

The day before my next visit, I ran my son over to the garage to help me flip the bonnet so I could get started on it the when I got there. With the bonnet flipped, I got to blocking, following the same process as I explain above. This time I used some cheap Walmart spray paint as a guide coat (get the flat black, the gloss black tends to clog the sandpaper a bit more) to block out the bonnet through 220-grit.

"Guide coat" applied.

Post guide coat blocking, other side.

One thing that I should have done is spray guide coat between each grit of sandpaper so that I could tell if it was getting better (or worse). I may have also done some light hammer and dolly work in there, but only very minor stuff (shhhh).

For the area around the headlight buckets and the parking lamps and turn signals, I mainly used the 4-inch soft block or my hand as these were tight areas. A red scuff pad worked here, too, if for nothing else than to smooth it all out.

Tricky area.

I got through 220-grit and stopped. I wasn't happy with the scratch marks that I had and I kind of locked up on what to do about it.

All blocked through 220-grit.
After some thinking and looking at my doors, which are almost perfectly smooth compared to the bonnet, I think I just need more paint. I stopped for the night at that point to ask questions on the SPI Forum.

Next visit:


My ace in the hole, hopefully, is the 3M palm sander that I have. I brought it out towards the end of the first video in this post. I picked up a flexible edge hook and loop backing pad, an interface pad, and some 320- and 400-grit sanding discs. By the way, I've been using the Dura-gold stuff that Amazon sells and have been happy with it. They didn't have 400-grit discs in stock for prime shipping, so I went with (and the link is to) a different brand called TigerShark, which incidentally is more expensive. I don't like it as much as the Dura-gold; doesn't seem to hold up as well. But, I did get 50 disks, so that may be enough not to matter.

As a little present to me, I also got a set of 3M Worktunes bluetooth ear muffs. These things are pretty cool. I usually have something going in the garage - music, talk radio, random podcasts - but I couldn't hear anything while I was blocking and doing other stuff. These things take care of that very nicely. The sync with my phone and voila! Entertainment!

With the palm sander all set up with 320-grit paper, I got to sanding. Much faster of course, but I was being very gentle, letting the sander do the work. I was especially careful on edges so that I didn't burn through to bare metal if at all possible. I didn't really have a problem with this, probably because the sand paper isn't very aggressive at 320-grit.

Once I got through the 320-grit, it was on to the 400-grit, following the same method. The scratches, however, remained. This makes sense, of course. If you don't work your way up through the grits, getting, for example, the 150-grit scratches out with the 220-grit paper, and the 220-grit scratches out with the 320-grit, by the time you get to the 400-grit, you're not even touching the 150-grit scratches...they're just too deep.

Example of some bonnet scratches.

More scratches, a bit easier to see.

These examples were on the bonnet, but the body was similar. I had posted these pics along with questions on the SPI Forum and everyone essentially agreed that I'll need more paint. Because I've got bare metal spots, I prepared to do full-strength epoxy (two coats) on the body and the bonnet.

By the way, I think I've mentioned this before, but that SPI Forum is just a good as my favorite forum. The people are understanding and easy on you. There are a couple of guys on there that do this stuff, or did do this stuff, for a living and they're experience is awesome. Also some high-end restoration guys on there, too, I think. So much great information.

Body all ready for more epoxy. You can see a good size bare metal spot behind the wheel arch.

The guy who has the next unit over was there, so I asked him to help me flip the bonnet and, with that, I got the wire tabs welded in. I had gotten these made and painted in epoxy (with a paint brush) quite a while ago (I don't even know how long to give a link to you). The epoxy needed to come off for welding, so I clamped the tabs in, marked the holes with a Sharpie, pulled them back off and got the epoxy removed. I couldn't get the flattened drill bit in there and the epoxy is very stubborn to come off, so it was easier on the bench.

Tabs clamped in and ready to get welded.

I've run into this before, but again I had the problem of finding a good ground for the welder since the bonnet is covered in paint. Fortunately, the very ends of the tabs were not painted. I had taped them all to a piece of metal so I could handle that vice the little tabs themselves when painting. These provided my bare metal spot and I clamped the ground strap right to them.

Problem solved!

I had intended to paint the body and the bonnet (standing it up on end) all at the same time, but the limited size of my "spray booth" made me nervous that I would bump something wet with paint or, worst yet, back into the bonnet and knock it over. I decided to just stick with the body for now and the bonnet will get love sometime in the future.

With the paint mixed and induced, it was time to spray and everything was going just fine until...the compressor seized up! That was a big bummer. I finished as much as I could with what was left in the tank, but it wasn't much. I got one coat on about half of the body, maybe a bit less.

Needless to say I was pretty upset. It's the garage mate's compressor and I've used it the most, so it was on me as far as I was concerned. I let him know and, turns out, the thing was pushing 20 years old and he was surprised it hadn't died already. He also had another compressor. A bit smaller, but oil-lubricated vice oil-free like the one I broke. That means it runs quieter and, more importantly, cooler, hopefully helping me with my moisture concerns. It has a 30-gallon tank (vice 60) and puts out about 10scfm at 40psi (vice 13 or so). I think it'll work, especially if I'm careful in how much I shoot at one shot. Another benefit of having such a small car!

We were able to get the compressor to the garage that night, but it will require some wiring modification (it's a 220v machine but has a different plug than the other one), but he's going to take care of it. I should be back in the painting business on my next visit!

The new beast!

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