Thread: Project Sebring GT Spyder

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Originally Posted by Hotrod46

Without knowing exactly how this was going to turn out, I didn't want to throw a bunch of money away on expensive raw materials, only to have most of it wind up as scrap. Turns out that was exactly what happened. I made a lot of scrap.

I think that's part of our promise or creed as a hot rodder! We make a lot of scrap but we always seem to re-use a lot of it in ways we never intended too.

Yeah, I hate to throw anything away. Even small corners that sometimes get trimmed off get thrown into a pile. They can be used for ready made gussets.

Edison is supposedly quoted as saying,"To invent you need a good imagination and big junk pile". Well, I definitely have the big junk pile!

On the face of it, the frame parts are actually pretty simple. Just a piece of flat bar with a section of angle iron welded to the back side to form a groove for the glass. Trouble was that most of these pieces were non-standard dimensions. This turned out to be the biggest time eater since all of these long raw materials had to be cut from larger pieces and very precisely, too. No one in my area had a shear that was both wide enough and sharp enough to do the 50" or so long parts I needed for raw material. I also didn't have access to a brake that was wide enough to cleanly bend the angle sections.



To get these, I sawed up 16 gage square tubing. This gave me long, crisply bent sections. These were then clamped in my milling machine vise and cut to width. I could only work the 6" or so that was actually supported by the vise jaws due to the part being so flexible. So the procedure was to cut 6" and move the part 6" in the vise and cut another 6". Each piece had two edges that needed to be finished. I started with 50" long sections, since I needed a little extra to get all the bends in. So each part had 100" of edge to mill.

All this sawing and mill work was maddeningly slow and each time a part was damaged during the forming process, I had to do it all over again. It did give me precisely dimensioned parts that fit together well enough that most welds were fusion welds with no filler metal needed.







On my first attempt with steel I tried to use 1/8" thick cold roll flat bar for the face and made the groove wide enough to fit the glass into commercially available rubber glass channel. All of this made a section that was just too thick. It stuck up proud of the posts. I knew this when I built it and thought I could get it to blend in as just another radiused step in the art deco posts, but it actually looked goofy, so that frame (which was about 50% complete) got pitched into the scrap pile and I started over.

Originally Posted by Hotrod46

All of this made a section that was just too thick. It stuck up proud of the posts. I knew this when I built it and thought I could get it to blend in as just another radiused step in the art deco posts, but it actually looked goofy, so that frame (which was about 50% complete) got pitched into the scrap pile and I started over.

The only word that seemed to fit;

Arduous - definition of arduous by The Free Dictionary
https://www.thefreedictionary.com/arduous

arduous - characterized by effort to the point of exhaustion; especially physical effort; "worked their arduous way up the mining valley"; "a grueling campaign"; "hard labor"; "heavy work"; "heavy going"; "spent many laborious hours on the project"; "set a punishing pace".

But when it's complete. I'll bet it'll be Stunning! I don't think we need me to look up that word too!?!? You got plenty of engineering and blood, sweat, tears invested.

34, that pretty much sums it up nicely.

On my next attempt, I used 14 gauge steel for the face bars and reduced the width of the glass mounting groove. I attempted to find some glass setting tape locally, but didn't have any luck. That is really just rubber "tape" that doesn't have any glue on it. It just wraps over the edge of the glass and gets wedged into the groove in the frame. This is how the glass in the original Healey frame was set. It's also how some vent window and door glass was set in American cars, so I figured one of the local auto glass places would have some. Both places told me that they didn't use it anymore and just set the glass with plain old black silicone. Both guys recommended that I go that route. I should have took that course from the start; after all, it's how I set the glass in my T-bucket frame many years ago. The silicone makes the frame building a little easier, too, since the groove doesn't have to be quite so precise.

I had another problem, though. Flat bar isn't readily available in 14 gauge, even from the online metal suppliers. So, I had to resort to cutting it out of some 14 gauge rectangular tubing and milling the edges straight. More slow work with each piece taking the biggest part of about 5 hours. This required a long jig to hold it while cutting.



This is what sections of square and rectangular tubing look like when they are ripped lengthwise. The heat from sawing and the internal stress in the tubing from it being formed cause the sections to bow. The thin angle sections straightened out fairly easy, but the flat sections had to be worked carefully or they would bend.



I rigged up a slip roll using a couple of flat dies and an old iron caster in my bead roller. It worked pretty good. The piece in the back in this picture started out looking like the piece in the front.





I think this qualifies as a proper bodge, but I will need an official ruling from somewhere that speaks the King's English!

I also had to make some more of the 16 gauge angle iron for the groove. Now it was on to the bender and this is where I had another "learning" experience.

A noble bodge for adapting availability to needed end product.

Very nice work once again. You sure making all those pesky issues near perfect now.

When I was using the 1/8" flat bar everything went very smooth, but it didn't go so smooth with the thinner stuff. I was bending this material edge on and was being very careful to keep the bar laying flat to minimize warping. I was going along good and then suddenly the effort required to make a bend felt very soft. On inspection, I found a very slight lengthwise crease in the part. I attempted to flatten this out with light hammer and dolly work, but no matter how much I tried, I couldn't get it out well enough (in my opinion)to be chromed. Well crap! Another part in the floor and another several hours of sawing and milling.

Thinking that I had somehow let the flat bar get cocked against the bending die, I took extreme care not to let that happen on the next attempt. All went well until literally the last couple of tweaks. Without warning, the bending effort felt soft again and I had another creased piece of junk.

This mess was getting very old, very fast! Two things were very apparent. I had to find a source for commercially available flat bar and I had to come up with a better bending process before I made another attempt.

First up, I scoured the internet again looking for 14 gage flat bar, but as before, I couldn't find any. The solution came when I decided to look into metric sized material. 2mm flat bar is available and that is only a few thousandths different than 14 gage. Not even enough to worry about. Sure wish I had thought to look at the metric stuff sooner! I still had to custom cut the angled material, but it was the flat bar that was the big pain in the rear.

With the material problem finally solved, it was on to the bender. I decided to build a 2-piece bending die that had a curved groove in it. This would completely support the flat bar and hopefully prevent the thinner metal from developing the crease that had killed the other parts.





This die was made by cutting another piece of the same brake rotor that I used on the first die and machining a curved step in it just a few thousandths deeper than the thickness of the flat bar. This was bolted together with the old die to form the grooved die. A couple of test parts were done and, with fingers crossed, I was satisfied that I had the creasing issue solved.

Mike: could Robert's technique to mount the lower edge of the running board skirts be adapted to mount your screen?
Just a thought.


1947 Biederman Truck Fender Repairs

I wish I had the metalworking talent and patience that you have, nice work!

Johnboy, I appreciate the idea. That could have been made to work. He formed that detail with a Yoder-type power hammer, so I would have had come up with another way to form it.

Unfortunately, I'm several months behind on these updates and I'm actually finished with the frame. I have a bunch of stuff written up and I'm just posting it up a little at a time to give everybody time to read it. Not keeping the thread up to date is a bad habit of mine, but the writing is something I struggle with and I usually wait until I'm in a writing mood.

Again, I appreciate the help and I'm glad you're enjoying this enough to follow along.

Seth, what few skills I have, have taken 60 years to acquire. The patience came from doing machine work for about 20 years for a living. Machine work forces you to be patient and somewhat methodical. I wasn't always very good at it.

The next attempt went about as perfect as you could hope for with these tools. I had some minor warpage, but that was easily worked out.

I used a stick of 2x3 tubing with some extra parts tacked on as a welding jig, along with just about every clamp I had, and soon had the lower section of the frame done.



I also had to make a curved aluminum part that clamps on the back of the main frame and holds a rubber cowl seal in place. A couple of shorter steel sections hold the ends down.







Finding something to use for this seal was also a real pain. I wound up using a seal made for slide out campers from Steele Robber products. It had a section that slides over the edge of something and locks on with friction. I only needed the lip portion, so I just cut off the edge portion.

Now that I had the bending technique figured out, the side parts went pretty easy.

The main problem with them was that they had to match the curves of the aluminum post exactly or there would be very visible gaps.



I added these angled pieces to the bottom of the side parts so that they could be screwed to the lower section. This is very close to how the original frames were assembled





After getting the sections done, I realized that there was still going to be a tiny amount of the frame standing proud of the front of the post. I had reduced the thickness of the frame and groove about as much as I could and had to resort to machining the seating area in the posts a little deeper. This all had to be done by hand since the curves of the posts are not constant. I had to eyeball the cutter and move the x and y axis' on the mill by hand to keep right on the edge without digging in to the shoulder that I didn't want to alter. Kind of nail biting work, but it turned out OK.

Whew...what a ride!!!! 8-)

Yeah 34, it's pretty much downhill from here!