fender shaping question

[AllyBill]

Originally Posted by filtersweeper

GOing to try this tomorrow. Should I try again with one piece or break it up into 2 or more? THanks everyone for the useful information. I'm thoroughly enjoying this type of challenge. Metal shaping is so cool.

Make it in three strips then if you get any of them wrong you can scrap it and have another go and you have not lost all your work. The old hands will easily push that shape in one but if you are feeling your way with it do it in smaller bites. We have all been there.

Will

[filtersweeper]

Originally Posted by Oldnek

Martin and Peter are on the money, you need to stretch the edge that goes to body and shrink the edge that goes to tyre (so Inner and outer edges aren't confused) up to that second marker line and shrink to your your convex line.
definitely don't need heat shrink marks on that panel.
Metalshaping looks easy, but it's very complex. and getting an understanding of how the metal moves and reacts, makes the whole process a lots easier.
The paper template will become your friend. Especially knowing where you need to put your shrinks and stretches.

PS: Undersized tyres would not be allowed here. Yellow Canary for sure

Thanks for the advice so far everyone. I continued to do alot of stretching along the outer edge more aggressively first on a stump with a big hammer and then on an anvil with the same hammer to move the metal faster. Lots of marks but I'm not concerned about that kind of stuff at this point. I'll refine my tools and technics as I learn. I brought another stump home today also. The stretching made a huge difference in terms of letting the convex shape to follow the over all radius of the fender arch. I could see that streching allowed it to lay flatter as well. My questions are now: Do I preform a little bit of tuck shrinking around the tire area as to tighten up the bulbus part of the fender where its to be convex and where the fender is tipped over and runs flat? Also do I leave the area flat (as in not curved over until it's time to tip it over? It seems like the convex part is too high for now just before it will tip over. Thanks everyone again. I'm here to stay! Pics:



This is where it's to bulbus (if that's the right word)

[filtersweeper]

Originally Posted by crystallographic

I made up a demo for you and took the pix.
- pix coming ....

Wow that's great. Good bunch of guys here on this forum thanks everyone.

[Peter Tommasini]

I presume that where you have N6 drawn on your panel is where you are going to turn the edge inwards on the wheel arch??
If so there is no need of shrinking .....if you re block that area all the way around you will find that you will keep you return and at the same time the edge will start to turn inwards (where it need to go) if you do this right you will find very little shrinking to be done over all, simply because while you are blocking in the area marked as 6 the edge below will shrink on it's own. As a fact....you will need to stretch the center of the wheel arch lip.
So here how to do this...
1 block (with a small blocking hammer area 6
2 the lip will start to turn
3 do this all the way around
4 when the edge is half way around...just hit the edge down without stretching it, from about 9 o'clock down to 6 o'clock and the same on the other side BUT!..... from about 9 o'clock upwards through 10/11 12 /1/ and 2 stretch that edge while you taking it over
I hope this clear for you... but this is the best I can do over the net
and please let us know how you go
Peter

[Oldnek]

Clear as Mud, Peter.
You forgot to mention a "Beer O Clock"

[Peter Tommasini]

Originally Posted by Oldnek

Clear as Mud, Peter.
You forgot to mention a "Beer O Clock"

Yea..... but only in Summer and then if you drink too much you do not know where O'clock is
Peter

[crystallographic]

Originally Posted by filtersweeper

Wow that's great. Good bunch of guys here on this forum thanks everyone.

Use a cross peen hammer to stretch the edge.
The dolly/anvil can be any curved hard surface. For bench work I support a track dolly with a shotbag and hammer on that.

P1170730 cross pein stretch.jpg

The back side of the work looks like this, and shows the pattern, orientation, and location of the blows.

P1170730cross pein stretch_back.jpg

For shrinking the reverse area in the center of your fender, I just heat a spot and drive it down with 4 or 5 swats with the hammer - slightly rounded face is helpful.

P1170732hot shrink_reverse.jpg

I heated and shrunk several spots, one after the other, but spaced them a spot apart on the first pass. Then I come back and hot-shrink the gaps.
This technique works best when heating to dull red in dim light, and having a proud spot to drive down. In this way you are using the geometry of the metal to support the shrink - without any tool underneath supporting the work.

I never quench my hot-shrinks on steel. It makes the steel hard - and metallurgists and long personal testing agree with this, despite old traditions and misinformation persisting to the contrary.

I think Jerry Gulley teaches "reverse-shrinking" and has been a proponent of the method for a long time, now. It works if you follow the procedure.

[filtersweeper]

So all of the advice has helped tremendously. THe panel is sitting even better and it's looking really good! I must say i am impressed
Anyways I have lots to learn and here are some more of those questions:
The panel sits in most areas however there are some zones that need work. Let's call the fender a clock and therefor top dead center would be 12, then moving clockwise: 1,2,3,4 etc. Around 1-2 o'clock it's not sitting right on the buck, it's like it need more concave but at the same time the entire fender needs to wrap around the buck longitudinally (in the long direction if that makes sense) It's not sitting on the last 3 o'clock station either. If it sits flat there then it raises on the other side at 12. I shrunk down the high parts that I marked "better" in the pics so it's getting close. WHat should I do from here? I'm thinking continue stretching around the top edge of 1,2,3 o'clock to get the material to lay on the concave zone of the buck and continue hammering on a dolly around 1 to 3 in the flat zone between rads to help the main long shape wrap around more: pics to better explain.

[Richard K]

You have made a lot of progress. The panel appears to be quite stressed. As a panel is worked (yours looks to have been worked a lot and severely in spots), it acquires localized stresses. For example, the torch shrinking pulls metal into a spot but a zone around it is in tension.

You need to do a wash-over in the wheel to relax the panel. Set your wheel tension so only slight pressure is on the panel. Too little pressure is better than too much. Then wheel the entire panel with the goal being to even out the metal stresses. When the panel is relaxed it should feel a bit floppy, not stiff.

As a panel is shaped, the shaping process changes the thickness of the metal. Where the panel is shrunk the metal thickens; when stretched it thins. The thickness differences will be very slight. In a smooth and relaxed curved section the variation in thickness will be a smooth transition from thick to thin. In a lumpy section or stressed panel the thickness variations will be erratic.

The wash-over wheeling will move the metal around enough to smooth the transitions without changing the shape. Wash-over also relaxes the work hardening that occurs in the metal. In your case it may well allow those trouble spots to lay down and match your buck.

[Peter Tommasini]

Jason...
might I ask( ) why you put heat on this particular reverse??
Peter