I posted something about this in the thread I started about wheeling alone. I trying to make a complete roof skin for a Datsun/Nissan 240Z. Partial patch isn't an option trying to do a complete skin. I have been trying to work through it and figure out issues that arise (best way for me to learn) and not ask for help but I do need some. Being that I can't wheel this alone and at the moment don't have the funds for Peter's hammer attachment I have been racking my brain as to how to do this. I remembered David Gardiner in his DVD demonstrated a way to make a low crown panel using a hammer and a steel table. Well I have a hammer and a steel table so I thought even though this is much larger I would give it a go. I've attached some pics at the bottom to help illustrate.
To summarize, I made a lot of profiles (42 I think
) and still need to make a some more but I wanted to get started as I was sick of sanding MDF. So made my paper pattern off of my good car (I have two of them) and transferred it to my blank, 20 gauge, closest thing I can get in the US that is close to what was used on the car. I think 1mm was originally used but taking some measurements with my calipers of Z roof skin, I was getting readings of .030-.033 so perhaps they used 0.8mm originally. Marked out my pattern on the blank and proceeded to start hammering on the table. This went surprisingly well and all things considered did not take to awfully long (few hours) to start getting some shape into the panel. Stopped every so often to set it on my good roof and judge the shape. Got the panel to sit flat in the center (front to rear). Looking at the panel it was clearly telling (as with the paper pattern) that I had too much material at the center edges (side to side) of the panel. I proceeded to hammer some more trying to continue to raise the panel and was able to get it to sit down better and make more contact in the center-out to each side. (hope that makes sense)
So the panel was still showing too much material in the center edges so I figured it was time to shrink as being only 20 gauge I don't know how much stretching would be too much. This is where I started having trouble. The panel drops a lot as it reaches the edges (side to side) so I needed to do some long shrinks. Actually had some success doing long shrinks (one was over 12 inches long) but I probably stretched the area some making the long tucks. As such I started to lose control of the panel a little. That is where I am now. The shrinks were pretty good especially considering they were all 8-12 inches long but the panel isn't doing what I thought it would. It actually started going high in front (to the center) of the longest shrink. And because I'm stretching the panel too much while trying to make these tucks I don't think I'm seeing the full effect of the shrinking.
Is my thinking correct? The paper pattern showed that I would have to shrink at the sides and to a lesser extent at the front. So my thinking was to stretch the middle first get some shape into it and then start shrinking where my paper pattern told me too. Then planish and check the shape with my profiles and adjust according. Once everything looks good turn the edges (block them in?) Am I on the right track? Is it possible to make the skin this way? I've got to believe it is. Any advice on the correct way to proceed would be appreciated. Or how one would proceed using the stretching method that I have to use (table and hammer)?
To summarize, I made a lot of profiles (42 I think

So the panel was still showing too much material in the center edges so I figured it was time to shrink as being only 20 gauge I don't know how much stretching would be too much. This is where I started having trouble. The panel drops a lot as it reaches the edges (side to side) so I needed to do some long shrinks. Actually had some success doing long shrinks (one was over 12 inches long) but I probably stretched the area some making the long tucks. As such I started to lose control of the panel a little. That is where I am now. The shrinks were pretty good especially considering they were all 8-12 inches long but the panel isn't doing what I thought it would. It actually started going high in front (to the center) of the longest shrink. And because I'm stretching the panel too much while trying to make these tucks I don't think I'm seeing the full effect of the shrinking.
Is my thinking correct? The paper pattern showed that I would have to shrink at the sides and to a lesser extent at the front. So my thinking was to stretch the middle first get some shape into it and then start shrinking where my paper pattern told me too. Then planish and check the shape with my profiles and adjust according. Once everything looks good turn the edges (block them in?) Am I on the right track? Is it possible to make the skin this way? I've got to believe it is. Any advice on the correct way to proceed would be appreciated. Or how one would proceed using the stretching method that I have to use (table and hammer)?
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