Sunday, August 31, 2008

Ready for sculpting

Today was another great day. Hot, too. Maybe I feel like I accomplish more when I bake in the afternoon heat. Maybe what I am measuring is suffering. Or sweat production.

Today I decided to take the Lotus. Usually I take my big old Dodge Carvan, which is full of stuff I can't leave at the shop, like paints and lubricants. Today I would't need any of that, so I took the opportunity to enjoy the Lotus.


The day started with an inspection of last week's welds. I spotted several places where the bond at the bottom was unconvincing, so I started there. While I was doing that I ran a little bead along each of the three joints, to prevent them from flexing relative to each other. Next I ground down everything -- I could leave a lot because the epoxy filler will cover it -- and pushed hard against each segment, to check the top weld. I found four in a row near the center than had not stuck. A little more welding, testing, more welding, until finally everything was solid.

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While I did the last pass of grinding I ran the wheel over the bare metal to give the filler a rough surface to hold onto. On when the latex gloves and on went the POR-15 epoxy filler. I always cut each part about 1/8 in. thick, because that makes a batch just the right size to put on before it starts to kick off. I went through maybe half a dozen of these batches.

I pushed hard to force the filler into the cracks and gaps, my thinking being that this stuff is somewhat structural and will help tie all the little pieces together. If the pieces move relative to each other the finish coat will crack.

When I had all the new parts done I still had some time left, so I filled in the places I had left uncovered on the first (left-most) patch. Next week I can get right to work shaping the entire piece.

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On my way home I stopped for gas. The Lotus fuel gage was reading beyond full, which meant it was getting low. When I made new tanks the sending unit ended up wired backwards, and physically the float cannot swing all the way up or down, so the gage reads empty when the tank is 7/8 full and full when it's 7/8 empty. The gage sits right in front of the passenger, and makes for interesting conversation. Anyway, to fill up cost $40. That's right. Slightly less than nine gallons, $40. Well, it is a Lotus. It's worth it.

Then came the embarrassment of the engine not starting. It never cranks enthusiastically, especially when it's hot. This was one of those times. Then it stopped cranking altogether. What happened next is why I buy my gas at Kahala Shell and not Costco or 7-11. One of the attendants brought out a jumper battery -- without my asking! -- and helped me get it going. No charge. I really do have to replace that lousy positive cable. Hats off to Kahala Shell.

Sunday, August 24, 2008

Finally Got It On

Today I finally got the last two rear window sill patches welded into place. Break out an extra ration of rum, I say! Huzzah!

These two patches were much easier to fit because the sill curves less in the center. I had to run the bottom edge of both through the stretcher one more time. Then, like the first two, I tweaked the upper tabs up here and there to get the best possible fit.

After all the tweaking the weld-thru primer I had previously applied was a bit dinged up, so I shot both pieces again. I also ground off the POR-15 in the places where the welds would go. And I drilled holes through the upper sill to facilitate welding.

The third patch went on easily, because I could hold it in place with vise-grips. The last one posed an extra challenge because there was no space for the vice-grips. To hold it in place I tack welded a thin steel rod at each end. My friend Tom held it in place while I welded.

I just got the last piece welded on when it was quitting time, so grinding and filling will have to wait. All in all it was a good day.

One thing I noticed about today was the heat. It was especially noticable when I was welding, when I wear a heavy long-sleeved shirt, thick gloves, and of course the helmet. Turns out it was 90 degrees in Honolulu today, which is as hot as it gets. My bay faces West and today I could have baked cookies on the E9's hat rack.

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Monday, August 4, 2008

Another Patch Welded On

I was hoping to pick up the pace by welding on the next three patches as a group. That is why I had previously painted all three with Weld-Thru Primer. Last week ended in a lesson about what happens when the desire to finish gets too strong. The patch for the right side still did not fit right, and instead of taking the time to tweak it the way I had the left side, I thought I could force it into position and let the welds hold it in place. The tack welds failed, and that was when I realized I needed to slow down and do what needs to be done. In my defense, it is not always obvious what the right thing to do is when you are learning as you go without a teacher. The trick to learning from your experience is to recognize and make use of learning opportunities.

In his book "Positive Coaching" Jim Thompson descibes a similer situation, which he calls a coachable moment. In sports, there are times a player can receive instruction and times they can't. There is no point in trying to explain some fine point of the game when the athlete is not in learning mode. As a rule, game time is not learning time. Even during practice there are surprisingly few coachable moments. This is why so many coaches complain that their players don't listen, that what goes in one ear goes out the other. What makes a successful coach is the ability to spot those coachable moments and make the most of them.

My point is that when I get all spun up working on the car the effect is the same as being "in the game." If I am doing something familiar I can charge along without worry. It's when I am doing something unfamiliar that I need to resist the temptation to put on my game face, because that is when things are more likely to turn out badly.

As I was tweaking the right hand patch I ran into a problem getting the top edge of the patch to fit tight againt the opening. The problem turned out to be the original seam, which is about 1/2 in. back. I did not want to grind it flush because that could weaken that joint, which could make my patch fail in the future. At the same time I did not want to rely on spanning the gap with the welder. I decided to drill a series of holes through the sill, one per tab, on or near the seam line, and to weld through those.

This plan almost worked. For some reason the outboard end ended up with a little more gap than I had expected. The only explenation I have to offer is that I relaxed my grip on the rod lifting the piece into place before the weld puddle fully hardened. I ended up trying to fill in the gaps around the holes and along the edge. The result looks messy but it should have enough strength. I did not apply putty because I think I need more welds along the bottom.

One last item. Previously I mentioned getting a welding blanket to prevent setting things on fire. For this session I did a lot of welding, and when I was finished it looked as if a bunch of oily rust flakes had been dislodged by all the grinding. It turns out the spots on the blanket were burn marks. I even burned a hole in my pants. Anyone contemplating welding on a car should consider a welding blanket mandatory equipment.

Second patch after initial weld.


Another view showing welds through holes in window sill. Inboard hole (net to vise-grips) not filled in yet.


After filling in more of the gap along the top edge.


After a little grinding. I think I need some more welds along the bottom edge.