Stretching a Model A Hood....continued

A few days ago I asked for info on stretching a Model A hood & got a lot of good replies, some said " don't bother, buy one ". Others asked for progress photos. I'm not a metal worker or a body man, but I love a good challenge, so I am going forward. Attached are a few photos. All responses are appreciated, both positive & negative. If you see anything in the photos that I should address please let me know.
Thanks,
Bob

 

Wouldn't it be easier to just make a new pair of top pieces?

 

Bob,

I like your attitude with regards to the challenge! It looks as though you have a nice plan and layout thus far. My only concern is going to be the springback from the orginal hood dimension. I'm sure that a little coaxing will render it compliant though
With that said, I think your approach looks sound. Be careful to incorporate some extra reinforcements on the underside seam so as to avoid it looking buckled once you add the new piece.

keep it up! Grant

 

I agree, there probably will be springback. Once I get this thing cut and clamped to it's final shape I will probably add a lot of underside support. My biggest worry is making the pie cut to remove the extra sheet metal at the high point. Actually, what I need is a dressmaker who has a good mental image of what happens as material is removed. I am resistant to fabricating a new hood for two reasons, #1 I don't have the skills or tools, #2 I like the look of the OEM hinge & belt line.

 

i don't understand why you need to strech your hood. my av8 flathead has the stock hood.

 

Chassis was fabricated longer to accommodate a flathead V8 with room to spare. I don't like a crowded engine compartment. I was originally going to go hoodless but changed my mind, want to try a hood top only. If I can't get this right than at least I tried. It's all in the challenge.

 

As for your concern about cutting out pie shaped pieces or overcutting, use a piece of paper so you know how much material you have to work with. Then, take long, narrow pie sections out. Don't finish weld it. Just a bunch of tacks to hold it in place until you are happy with the general shape. Once you have the desired contour, move forward with welding.

Like you said, if it doesn't work, you tried. A slip roll will be your best friend if it comes to that

Grant

 

Have you put a rule across the length of your hood over the radius? Does both surfaces of the hood touch constantly with the rule?

my weekly metal work blog www.themetalsurgeon.com

 

Check picture 3.Your profiles are way off,this will not work.Unless your going to cover it 1" of cake!Save your time and efforts.

my weekly metal work blog www.themetalsurgeon.com

 

glad you are posting pics cause im about to go thru the same challenge.... looks good so far.

 

I noticed the profile in the 3rd pic as well? Looks completely different than the side profile of it mounted on the vehicle.

If it is that far off, like in pic #3, the pie cuts would have to go the full length of the panel. I would have to look at it up close to see exactly what you are working with.

Can you take some pics of the front to back profile while mounted on the vehicle?

 

Something else, you will need to pie cut the front AND rear sections to distribute the contours evenly. It is going to be a bunch of work if the panels are that much off.

Not saying I wouldn't try, but there will be a lot of linear feet in welding when all is said and done.

If you have time, go for it. If time is money, a slip roll and hinge are in order

Grant

 

yes, where the hood was split the profile is correct at the point only.If you then move the 2 sections apart 0.5mm or more then the profile perimeter gets longer. What you see in pic 3 is the back section moved back and the profile perimeter is too short in length. No amount of pie cutting will correct this because you are short of material in the first place.

I would advise anyone thinking of doing this ,not to in order of not destroying your hood.

my weekly metal work blog www.themetalsurgeon.com

 

You are right, it will never work. A few minutes with a straight edge will show you why.

 

I totally agree about not being enough material on cab side! What I was implying is what you take away from the radiator side would need to be added to the cab side. That is if you distribute evenly. It is going to be a major challenge.

A new piece (hood pieces that is) can easily be hand formed which is nice. Grant

 

Think you might be better off adding extra material from the front as shown it the pic...then spread it a little to fit the grill shell. It wouldn't take much.
Here's a link to the entire process of stretching an A hood from the Tech archive:

http://www.jalopyjournal.com/forum/showthread.php?t=298817

Rootleib prices are: hood top-250; custom length-150 = 400.00 just for a top.
I say keep trying!

 

The real beauty of the HAMB is that you get exposed to lots of points of view and in this case, a SUPER ARTICLE on stretching a hood.

As I pointed out in my own build report.....you don't necessarily need to know how to do a task....only that you want to do it so bad that you are willing to dive in. First thing you know, the answers will come and the task will be completed.

(Great work, by the way!!!!) Keep up the faith in yourself.

 

Honestly, Go to the metal shop and grab a chunk of .063 3003 aluminum, make a card board pattern, cut it out and roll it over an oxygen bottle or a support pole or a telephone pole. There is nothing exotic about making a hood at all. I'm sure there has to be a sheetmetal place of some sort locally that can roll a bead for about 20.00 or so. What you are looking at there is going to be hard for the best of metal guys to do with the best of skills. I truely understand doing it yourself, but I also know the after effects of making your self crazy trying to do the slightly impossible.

 

Wow, great responses.
Photo #3 was purposely taken to show the major problem.
I'm still going to give it a try. You learn from your success & failure.
By the way, is bondo sold in 5 gallon pails ?

Bob

 

5 gallon pails...hahahaha
As a complete newb in regards to sheet metal work, would it be better to add to the front or rear of the hood instead of the center?

 

One rather wide leather strap will cure the problem.

 

When I first decided to try this I noted how the hood narrows from the cowl to the radiator shell. If I continued this rate by adding a few inches to the front, the hood would be too narrow for the radiator shell. The same goes for adding to the rear, cowl side. The hood would be too wide for the cowl. I figured I'll try the center & keep the contours at the radiator & cowl correct. We'll see.

 

I admire your ambition, but you are wasting your time cutting and pasting that thing. You need to make a new top cutting and pasting isn't going to work....But You'll be real good at welding and grinding.when done.

Once you make a pattern and cut out the metal you are using for the hood it will literally take ten minutes to bend it to fit.

 

I'm getting a lot of feedback telling me I should buy some sheet metal, make a pattern, and fabricate a new hood. It's probably very good advice, and is a very serious plan B.
My only problem is that if I don't make every effort in altering the original hood, I'll never know if I could have done it. Some call this OCD, I call it curiosity and a challenge.

 

Like I said I admire that type of attitude, please keep us informed of your progress.

 

You forgot to add ,i have plenty of time to waste!


my weekly metal work blog www.themetalsurgeon.com

 

it might not be a waste of time, even if its unsuccesful the man's gonna learn something....i think thats his angle on this.

good luck dude...i'm interested to see how it turns out!

 

Just try this but first realize the hood is tapered vertical and horizontal.
The cowl shape stays the same, the rad shape stays the same but the distace between the two has changed.


Ok cut a wedge shaped piece of wood, make it a foot long 2x4 that tapers from 3.5 to 2.5.

Find center, mark one end A, each side of center B, & C the other end D. Now cut thru the center and add a piece that's 3.5 inches long in the middle.

Now line up points abcd
You just can't do it .
Now cut a new wedge @ 15.5 inches long that tapers from 3.5 to 2.5 and see how different it is from the one you cut and added. Really want to have fun, taper them on the otherside from 1.5 to 1 before you start..

 

I dont understand if a professional and other professionals are telling him it wont work i dont understand the point of the exercise.

for the people who dont think its a waste of time,they havnt sat down and thought this through logically.Its all about angles.

The guy was looking for feedback and really choosing to ignore advice .Its not about choosing a color for a car ,its about hard facts.

If someone told me it wouldnt work and explained why,i would take their advise.

my weekly metal work blog www.themetalsurgeon.com

 

OK guys, I admit it is a monumental task to fight the laws of physics. Some say I'm a fool, maybe they are right, but I am still gonna try. Unfortunately I did have to give up my afternoon soap operas. How are the desperate housewives doing ? I'll be in the shop the next couple of hours, making the cuts & taking some photos. I'll try posting the photos tonight, for those that are interested. In the end, some will laugh with me, and some will laugh at me.