Finishing Up Sill Rework, Some Wet Sanding & Stud Repairs | Roundtail Restoration

Time to get caught up. This post will be a bit long in doing so. I finished up the sill rework to include getting seam sealer in the gap. That worked out really well thanks to a recommendation from one of my regular viewers. Speaking of which, to the video:

Earlier this month I ordered what will hopefully be the last of my paint supplies from SPI. I got another quart kit of epoxy, but this time in white. I'll use this as my final sealing coat (it'll be reduced by about 25%). I'm going with white instead of grey to give the red a bit brighter of a base to go down on. I'm not sure that it'll really matter, but hopefully it'll give it a bit more "pop" than it would have over grey epoxy.

I also ordered another quart of medium red as I used about 1/3 of a quart for tinting the Raptor Liner. My concern is that I would run out of red in the middle of painting. That wouldn't be incredibly terrible but for the fact that all of the base coat cans should be about evenly combined and mixed to ensure a uniform color. If I had two quarts that I mixed, than ran out and got a third from a different batch, the color may not match. That would have bugged the hell out of me. So, I got another quart. I may not use it, but better safe than sorry.

The last thing that I got was some more Wax and Grease remover but this time, it's solvent-based instead of water-based. For whatever chemical reason, the water-based stuff shouldn't be used to clean base coat. Since the solvent-based stuff is okay on anything and I wasn't sure if I was going to need to spray the base coat, I got a gallon of it. It's supposedly really good to clean your oven, too, so I may try that when I'm all done with the paint job. Good excuse to spend the money right there!

More paint and supplies. That's a bit over $200 worth right there. Stuff's not cheap!

Toward the end of the last post, I wrote about putting down some body filler in various spots to clean up some of my weld seams and panel-to-panel gaps and such. I did more of that, including some minor filler pitting that I had on the bulkhead repair that I did a forever ago.

Polyester filler are the sill-to-upper-A-post seam.

Once that filler was all dry, I sanded it all smooth, blocked everything out through 320-grit and hit the car all over (exterior) with another round of epoxy primer and left it to cure for a few days.

With fresh epoxy covering the bare metal, especially around my sill rework, it was time to get the rework finished up with filler and seam sealer. I did a couple of applications of filler and got it all blocked out. Turns out that area is now better than the driver's side, so quite a turn around.

For the seam sealer application, I put blue painters tape on either side of the gap (recommended by a viewer) to bound the area and filled it will seam sealer, running it down smooth with my finger. This will give me a flexible seal in the seam that hopefully won't crack with the bumps of the road.

Seam sealer. Hard to see since it's about the same color as the epoxy.

There wasn't a whole lot else to do that night since it was towards the later side and a school night, so I decided to give wet sanding a try. Turns out I bought the wrong sanding discs (not wet/dry), but with some water and my 3M DA sander, I went through 400-grit wet (they held up good enough). Smooth as silk! I didn't take any pictures because you really couldn't tell the difference unless you felt it. That was about it for that visit.

When I came back again, my first job was to get the big compressor fixed. I found both a start and a run capacitor on, where else, Amazon and bought them both. Capacitors can be tricky to verify broken, so I played it safe and got both (under $20 for the pair). I swapped them out and the compressor started and ran fine...for about 3 minutes. It locked back up on me. So, I took it all back apart again, cleaned some contacts for the centrifugal clutch up, put it all back together, and it has been running strong since. Not sure that I actually needed those capacitors after all, but it's working, so good enough for me!

Horrible picture of the old starting capacitor. Run capacitor is to the right of the shot.

As far as Dorothy goes, my object was to start back in on the bonnet. I decided to stop wet sanding the body. With it needing to stay in the "paint booth" because of my limited room, I didn't want overspray from other things that still needed to be painted to mess up my wet sanding. Therefore, I covered it with plastic and moved it, sideways, to the back of the booth.

I put the bonnet on the rack, inner side up, and got to work on that. My only goal was to get it in epoxy following some block sanding and such that exposed some bare metal, especially in the areas under the wheel arches.

Because this area was tight, I purchased a Harbor Freight touch-up spray gun. As always, I used a coupon and, for about $25, it was mine. It's only got a 0.8mm tip (the epoxy calls for a 1.4 or 1.5mm tip) so I was concerned that may be an issue. Only one way to find out!

Ain't it cute?!

Because I struggled with is so much when I was setting my gaps, I also wanted to get the transverse support tube installed prior to painting color so I didn't mess up the paint trying to adjust it. I measured the gaps between the end of the tube and the wheel arch support brackets after getting my gaps all set (and before removing the tube) so that I could put it back in about the same spot.

Measurement prior to taking it apart.

With that, I put the tube back in and tightened it down...or not. Either because I wasn't that carefull or just years of vibration (or both), the threads on the studs had flattened out so much that I couldn't tighten the nut. It would only get so (not) tight, then just kind of skip.

The studs. The rear one was compromised by functional, but the front one was shot.

I brainstormed for a bit (you can see that about here in the video) and was ready to drill the bracket out and replace the studs, but decided that it would be better to just paint what I had (I had already mixed the epoxy and didn't want to waste it) and worry about the stud after I asked for advice on my favorite forum. Thanks goodness I did!

Following paint.

The little paint gun did very well. I was actually quite impressed with the coverage and the spray pattern. It allowed me to get into the tight spots, actually putting it through the headlight bucket opening, to get to all the tight areas. I'm sure there are other options out there for a touch-up gun, but I'd recommend this one if you don't have your heart set on something else. The true test will be when I need to lay down red and clear coat. I may change my tune then, but we'll see!

Painting wrapped it up for that visit and I came back for the next one armed with a solution to my stud problem. A gentleman on the forum, a machinist by trade, recommended running a metric die on the stud and converting it from the 1/4-28 UNF thread that it was (want to know what that means? Watch my threaded fastener video) to a 6 x 1 metric thread. The size difference was just small enough to cut fresh metal for the metric size, but not so much smaller that I would compromise its strength. It worked like a champ!

Post- repair.

If you look closely at the picture above, you'll notice that the threads kind of flatten out in the middle. That's where the damage was. However, I cut just enough metal that the nut gets good purchase and does tighten. I didn't get crazy with it, but I think it's good enough. I also cut down the rear stud just to be sure.

All better.

With that all done, I went for another round of epoxy in there to cover the minor portions of the tube that hadn't gotten a full coating. I also did a random assortment of other pieces (door hinges, headlight buckets, windscreen brackets, etc.).

All sorts of stuff ready to paint.

I also cleaned up the hardware that held the bonnet pivot support tubes. I had cleaned these all previously, removing all of the old paint. With the summer's increased humidity, this stuff started to surface rust since they were original fasteners and, therefore, not zinc plated. I scuffed up those and a few areas in the wheel arches and hit those with epoxy primer as well. There is another coat or two of Raptor Liner in it's future.

Passenger's wheel arch, rust protected.

All those parts above, painted.

That was about it. You may notice a strange, large, white piece in a the picture above. I mention it in my video a few times. That's a wasted 240Z fender that my garage mate kindly donated to the cause. I'm going through the whole bare metal to clear coat process on that to make sure my procedures work. It's still in the epoxy phase, but here's the video so far on that:

That's all I've got and I'm all caught up...for now. Thanks for reading and watching!

Sill to B-Post Rework | Roundtail Restoration

Sorry, folks. I've made several videos since I last updated my blog, but only two of them are really work in progress videos. However, I did do a series on redoing the seats, which I'll provide below:

Definitely a topic that lends itself much more to video than it does words. The link is a dedicated playlist for all three videos.

I also am in the midst of a 4-part series on threaded fasteners using the lessons and directions that we used in the Navy. It's a lot of me talking, but it's full of information. Here's those:

I tried to make these videos shorter, but I talk to damn much. I should get the last one out soon.

As for the work that I did in direct support of the restoration in progress, most of it has centered on some re-work. I never liked the area where my passenger's side sill met the B-post. While contemplating the extent of that rework, I had a sort of epiphany as I stared at it; I'm probably not going to have the car on the road this season, so I may as well just get it fixed right. Otherwise, it would stare at me every time I walked up on the car.

Construction-wise, the sill sits on top of a flange in the B-post. I don't think it was ever spot-welded (from the factory) in this area, but it was brazed.

When I was struggling with my gaps, a very kind gentleman from England who works in the industry was kind enough to send me some pictures of the last Triumph Spitfire, in Inca Yellow, that rolled out of the factory in Canley. It rolled right into the British Motor Museum and is the top car in a 3-car rack (along with a TR6 and MG Midget). It's only got about 10 miles on it, so this was the standard coming off the line in August of 1980. One thing I will mention is the gentleman told me that the tooling, jigs, and fixtures they were using by that time were over 20 years old, well past their "sell by" date (which is about 7 years).

The sill-to-B-post transition. Notice the brazing spot.

As an FYI, this is the front sill cap. Guess that little edge that I left on mine should have been ground down.

On the stop shelf. You can just see the top of the Midget below it.

Now I knew the look that I needed to recreate. The metal had been damaged a bit when I was putting the sill in, causing the gap. Since there was no access behind it, I had to cut a window to make the repairs.

Tracing out my cut area. Sorry that I didn't take a "before" picture.

This was easily accomplished with a metal cutoff wheel.

The window to the repair.

The flange on the B-post needed some help. It had a few holes in it and just needed some love and straightening. I did the best I could.

After some work.

Once I got the flange as good as I was going to get it, it was time to fit the cut-off piece back up to check fit. Not so hot.

Huge gap! Time for some weld build-up.

I did a weld build-up right at the vertical-to-horizontal transition near the top. This corner should be relatively sharp but was rounded at some point during the sill replacement (or old sill removal).

The step of the flange in the B post was deep enough that the sill didn't rest on it (guess that's why they didn't spot-weld it). But, I needed something make up the gap, so I welded a flange on the cut-out piece and removed some of the damaged flange that was therefore no longer required. It was kind of a hybrid flange, I guess you could say, but it made it easier to get it fit up.

Damaged flange area cut out. The weld build-up in the corner of the B-post is also easier to see here.

With that figured out, it was time to weld it all back up. Getting it all sized and adjusted was not that easy since it was a blind weld, so to speak. I couldn't hold the cut-out piece in place with a magnet and see what gap I was going to get at the same time, so I used some tape. The video does a better job of showing this. Eventually, though, I got it lined up and welded in.

Piece replaced. That rounded corner at the union is much sharper now.

And with minimal gap.

With it all welded in, I got some fiberglass filler on it to provide some reinforcement (I should have epoxied it first...grrr). I was careful to keep the fiberglass out of the joint itself because I was afraid it would eventually crack since I'm sure this is a flexible joint.

Fiberglass filler applied and curing.

Sanded down good enough.

I sanded the fiberglass down to get the high spots off. I'll get it into epoxy primer on the next visit and then do "normal" filler work on it to get if flat.

What the gap and union look like after the repair.

Once all of the filler work is done and epoxy is down, I'll use seam sealer to seal the gap that remains. It should also give it a cleaner look as well.

Speaking of cleaner look, I also used some polyester filler, after scuffing the epoxy, to fill some of the areas on the upper A-post that needed it. I'm not too concerned with this area since it'll be covered by the bonnet a majority of the time, but there were definitely some spots that needed the attention. Namely the sill to A-post area had some decent gaps. The polyester filler, along with the epoxy that will go over it, should keep any moisture out of there.

Polyester filler applied and in the process of being sanded smooth.

Next post, I'll finish up with the sill repairs and move on to the bonnet, which also gave me some problems. Thanks for reading and watching!

Painting Mistake and Wrapping Up the Body | Roundtail Restoration

Holy cow! I just looked and it's been almost a month since my last blog update. Whoops! I did have some vacation in there, so there was that, but I'll try to get caught up here somewhat.

First, the new compressor works fine, but I don't know how to clean a paint gun! To the video:

I was able to get back over to the garage within a day of the compressor failing so that I could spray the epoxy that I had mixed up when the compressor failed. The pot life on the epoxy primer is north of 72 hours (temperature dependent) and I was at about 36 hours since mixing, so well within the window.

Given that, I gave it a quick stir, set everything up and laid the paint down. This is what I ended up with:

Looks like my Raptor Liner!

That wasn't good. I recognized it after laying down the first coat and decided to lay down a second coat. The texture wasn't too bad and I figured I could block it out. But why, oh why, did this happen? Turns out my lack of experience, and tendency to plow through, led me to miss obvious signs of a problem.

First, I had to crank open the paint supply valve on the gun much more than I normally do based on my pre-paint testing. I normally do about 1 1/4 turns open on the supply for my first epoxy coat. I needed over 2 turns this time. That was my first indictaion.

Second, the spray pattern itself was kidney-bean shaped. This shape is indicative of either a clogged fluid tip or air cap. I knew something was up, but wasn't sure what. But, again, I plowed through, resulting in two wet coats of textured epoxy. While the look was cool, it wasn't what I wanted, of course!

The spray pattern.

After I put down those two coats, knowing I had a problem but not why (yet), I called it a night before I did any further damage.

I returned to the garage, having figured it all out after asking around on the SPI forum and got to blocking. Fortunately, though it took a lot of elbow grease, I was able to block all of the texture out.

The dark areas are where I haven't blocked down to, yet.

The passenger's rear wing, post-blocking.

I guess one good thing about this, in hindsight, is that I got another good blocking session out of it. I started with 220-grit because I didn't want to burn through if I could help it. While this took more time to get the texture out, it did provide another chance to get everything flat again. Got to always look for the positive in learning something!

With that mistake taken care off, it was onward and upward, with build primer next. I did about 3 full coats of build primer, waiting 5-minutes in between coats to let it flash.

Build primer done!

That was all I had time for that visit and I returned the next to start blocking. I remember to use some guide coat this time and started blocking it at 220-grit. It went fine with some burn-through areas to bare metal, but I expected that. 

Passenger's side, post-blocking.

After that, I broke out my 3M random orbital sander and sanded it all with 320-grit. This was very nice and a hell of a lot easier than blocking by hand. From my research and a bit of common sense, once you start getting above the 200's for sandpaper grit, you'd really have to stay in one area for a while before you start to make a sizeable dent in the paint.

I'll hand block out to 220-grit, but above that, even with not much experience, I consider myself safe to use an random orbital sander from that point out. One other nice thing about random orbital stuff is that, unlike direct-drive sanders (a gross example be an angle grinder), the random orbitals will stop spinning if you apply too much pressure. That makes it a bit forgiving.

Don't get me wrong, you can still mess up your paint and cause some waves, but it's a bit harder to do with a random orbital. The same goes for polishers, but I won't need to worry about that until after clear coat!

Speaking of clear coat, I tried to simulate it by spraying down the driver's side rear wing to get a look at how bad it was, waviness-wise. I was pleasantly surprised. Not too bad. But, I was ready to be done with that stuff, so that's all for now. Cheers!