2008 Off to a good start

I had a great day at the shop today. First I finished what I started last week, making templates to align the section under the rear window. After that I removed the trunk and cut away the rusty piece with a die grinder.

Last week began with making a cradle for my welder's gas bottle. It's very simple, just 2 x 4s nailed together. I angled the bottle so that the regulator doesn't stick out from the cart.

The templates are made of aluminum. Their purpose is to locate the peak of the window opening after I cut away the rusted section. I might of made them too precise, but I wasn't sure what I would need. Turned out to be very tedious work, file and check, file and check ...


Simple wooden cradle for my argon gas bottle. I tilted the bottle so that the valve and regulator do not stick out.


Fabricating templates from aluminum to position patch.


Two shots of the trunk hinge mechanism before removing. I scribed a cut line with orange grease pencil just above the top of the weather-seal lip.


After first pass with cut-off wheel.


At last the rusted out piece is out. The area inside this boxed-in section looks better than expected.

Next job is to measure for second bend of replacement section. I now plan to put the top under the existing piece to minimize interference with window. As I am making the patch I will treat this area with POR-15.

Finally Getting Good Welds

Yesterday I practiced the patch welding process again, and this time I took a lot of pictures. This is the plan:



After cutting off the end of my previous practice weld with a die grinder and cut-off wheel I used my grinder to smooth the edges and polish off most of the surface rust. The next time I do this I will paint the exposed surfaces with weld-through primer, which is supposed to help prevent rust in the joint. I also foresee a role for POR-15, brushed liberally along the joints after welding.



This is my pneumatic flanger. Got it at Harbor Freight. I will use it to bend an offset along the edge of this piece. In practice this will most likely be the edge of the original sheel metal.

At this point I ran into a problem. My nice new flanger would not flange. After a lot of fiddling around I discovered that the swivel head -- the black piece -- does not exactly swivel. It threads onto something inside. I had swiveled it enough to unscrew it enough that the jaws no longer met. All it took was a few clockwise turns and I was back in business.



After flanging. The new flange is on the left.



The flanger also has a hole punch, located closer to the body. Here I used it to punch holes one inch apart, which is about the same spacing BMW used for the spot welds around the rear window opening. You can see four of the punched out bits laying on the table. They exit through a hole at the end of the head, which is to the right in this picture.



For my previous practice I just laid the two pieces on the table. This time I decided to clamp them tightly together. The warp might be from the flanger, but I think it was from the heat from my previous welding practice. Something to watch out for.



All clamped tight and ready to weld.



After welding. Sorry, no pics of me in my welding regalia. For that I'll need someone else behind the camera. I held the gun closer to the work than before, about 1/2 inch, and held it on each spot for about five seconds. Each hole was completely filled. This is the first weld I have made that I consider good enough for the car. Notice how clean the welds are, with no flux residue. All those recommendations to use shielding gas were right.



The flip side. In practice this will be the outside. There is a mild, blue burn mark at each weld spot, which I think indicates proper weld penetration. The joint was absolutely solid.

Today I decided to practice welding with the work vertical, which is how it will be most of the time on the car. I have had people tell me that vertical welding is a lot harder. They were wrong. I laid down several perfect beads in the clear area next to the weld spots, without any problems whatsoever. Nice smooth beads with no splatter and good penetration.

Inspired by my success, I laid out and made the first bend in the piece that will replace the rusted section under the rear window. (See "I Have a Life," Oct 12, 2007). I was in a rush so I did not take any pictures. My bad. I used a heavy U-channel piece that was originally a bumper, and suprisingly straight, to clamp my sheet metal to the steel table with 9/10 in. hanging over the edge. I bent that part down by whacking it with a big hammer and a piece a 2x4 wood to spread the impacts. Many, many impacts. If the result needed to be straight this would need to be done on a brake, but since the result will be curved, which means a lot more hammering, a little stretching is not a problem at this point. The important thing is to have the two bends the correct distance apart, and the correct angle.

The shop will be closed this Sunday and again on Wednesday, along with the usual Monday and Tuesday. The next chance I'll get to work on the car will be Thursday.

One last thing. I went shopping yesterday for a cart to put my welder on. The best place in Honolulu to get that sort of thing, Kilgo's, closed a few months back. I went to Home Depot and the only thing they had was made of plastic. The good news is it won't rust out. The bad news is, welding sparks will burn holes in it. I think Sears Craftsman has what I want. I should watch for an after Christmas sale.

Welder Up and Running

Last Sunday I set up my new welder. I ended up with a bunch of questions and I could not get the wire to feed all the way. Yesterday I stopped by Gaspro on the way to the shop and got answers. Very nice people there. At the shop I slipped off the nozzle hood and saw a short piece of old wire stuck in there. I managed to pull it our with needle nose pliers and the wire fed fine after that.

The helmet works great. Simple to set up and once that's done all I have to do is put it on. It makes welding much easier than the hand-held sheild that came With the shop's little Lincoln.

My practice welds are still not good enough for real work, but they are a lot better than before. Today I'll take pictures of a practice patch.

Got My Welder

Day before yesterday I picked up a gas MIG welder from Gaspro. A Miller 140 with Auto-Set. Got a great deal, too. It was the last one they had, their demo unit. It isn't clean and shiny, but I figure it looks the way it will look after a day or two at the shop anyway. It did come with a two year warranty. I spent the money I saved on a cool auto-darkening helmet.

I had to buy a tank for the gas. The salesman said that for thin mild steel I should use an 85-15 mix. I think one is argon and the other is C02. I have no idea what effect changing the ratio will have. I have a lot to learn.

Another thing I had to buy was wire. I got a small spool of 0.023, the smallest size they had. The next time I'm at the shop I'll get the alloy and part number so that I know what to buy in the future. I also had to buy a pack of tips that go into the gun that matched the smaller wire. So, remember, changing wire can require a different tip.

Honolulu is such a small town that as I was getting everything ready one of the salesmen said he went to school with my son Matt. His name was Gordon. The guy who recommended I use 85-15 gas. This is not an isolated case. The same thing happened at my neighborhood NAPA store and at Starbucks in Manoa. In Hawaii, everybody knows everybody.

POR-15 Rear Window Area

Yesterday I set out to treat the area around the rear window opening with POR-15. The bottom and sides. I'll do the top when I do the rest of the interior roof. This is in preparation for welding in the new section between the bottom of the window and the forward edge of the trunk.

The flange that the window sits on consists of two or three layers of sheetmetal spot welded together. Along the right vertical joint (the C-pillar) the gap is filled with lead, but along the bottom and left side there are many gaps.



The first task was to remove the old paint and what little loose rust was present. For this I used a die grinder and at first a synthetic wire wheel followed by a real wire wheel. After blowing all the dust away I washed the area with Marine-Clean, and when that was dry I brushed on a coat of Metal-Ready. The instructions said to keep the area wet for fifteen minutes so I kept going around and around.



Up to this point everything worked fine, but here is where I ran into the problem I was concerned about. I gave the Metal-Ready coat an hour to dry, and after an hour it was still tacky. I had to call it a day without applying any POR-15.

The shop is closed Mondays and Tuesdays, so it will be Wednesday before I can even attempt to apply a coat of POR-15. This area deserves two coats, which means going again on Thursday.

Painting projects are difficult for this reason, especially when you only have one day a week to work on them. Surface prep takes a long time, and waiting for something to dry chews up big chunks of valuable time. maybe a hair dryer would help.

Update: Pics to show how POR-15 turned out. First two show zinc (white splotches) where Metal-Ready converted rust, before applying POR-15. The rest show treated area. POR-15 brushed on easily.

This job used no more than half of the very small can of POR-15 that came in the starter kit. I poured it out into a clean soup can. After I was done I did not bother to clean up, just tossed the tin can and brush.

More Hammering

Last week the shop was closed for Veteran's day. Today the news was that the plasma cutter is still broken, so I spent my time finishing that little patch I started last time.

This is a patch for the lower right corner of the left tail light. The opening in the body is flanged, and the corner appears to have been radiused to follow the weather striping. I cannot say for sure because both sides have rusted out. The sections that remain have sharpe, 90 degree "Z" bends. The left side of the opening is curved to follow the form of the light fixture, and there the angles are less severe.



My guess is that this corner also was not as sharp as the section that remains. Even so, to get a good fit my patch needs to start with sharp bends. The top part (right side of opening) is easier because the indentation is only3/16 in. The bottom is harder because it is deeper, 3/8 in.



The photo below shows the result of a day's work. Basically I shrank the upper surface and streatched the lower, working the softly curved bends with the pick hammer to sharpen the bend. The shrinking hammer is the one with the teeth, which leaves the surface sparkly.



The next photo shows a side view of the deeper side, which will go at the bottom of the tail light opening. The top bend is sharp, but the bottom is stubornly soft and the narrow piece in between runs at about 45 deg. instead of 90. Even so, this might be good enough. All I need is for the light to fit and the bends to be covered by the light fixture.

Hammering Away

The plasma torch still is not fixed so I shifted my attention to the troublesome rear panel. I had planned on using the flange tool there instead of my original idea of welding in backing plates.

Looking at the area again, with the tool in my hand, I had to admit that the job was not as straightforward as I had thought. The damage around the tail light will require some complex patches. I decided to start with the long, narrow slot I had cut just below where the trunk floor attaches to the rear panel.

I had tried to remove as little material as possible. My problem now was that I could not get the head of the flange tool through the slot, so I used a die grinder to cut the slot wider.

The Harbor Freight flange tool works great. The only problem I had was with paint getting stuck in the jaws. I ended up grinding the outside down to bare metal with my 4" CP grinder. I finished with a coat of Rust-Prep followed with a coat of 3M Weld Thru Primer.

I spent the time waiting for the Rust-Prep to dry banging on a piece of steel with my new hammers. I chose a rediculously difficult task, the compound curve I will need to make at the lower inboard corner of the left tail light opening. It turned out better than I expected, although it is far from adequate. You have to start somewhere!