|12-23-2005 06:23 AM|
|Lost in NJ||
I must add to this thread as some people made some incorrect statements.
I have sandblasted 3 cars and not found a single distorted panel due to sandblasting. I even tried to warp a panel and could not.
The secret is to understand what you are doing.
I run a pressure blaster at 40 psi.
I open the sand mix valve on the bottom till I can just make out that sand is in the stream.
This gives me low energy impact. I have a small amount of particles traveling with moderate amount of energy. It slowly takes everything off.
On the larger sheet metal panels I try to keep an angle to the work, though my testing proves this is not needed. I have even blasted thin French car metal with no distortion.
We started blasting our own parts when we paid to have a guy blast some Model A parts. They all came back ruined. Of course, they were done with high pressure air and a large quantity of sand in the stream.
For safety I used an air fed hood and a respirator. Sorry guys you only live once and it only costs a few $$ for such protections.
|01-31-2005 06:31 AM|
Sounds like you're doing a great job! Keep up[ the good work.
I look forward to seeing your pictures.
|01-31-2005 03:57 AM|
Hmmm, went paint shopping today, I can't find an epoxy primer for the life of me. Everybody wants to sell me etch primer.
Randy what's the verdict, you recommended a few coats of epoxy and then a urethane primer. I sanded a very small area yesterday and the metal is not as bad as I thought it was, it probably won't take as much build to smooth it out as I first thought. If it's smooth enough just from sanding can I get away with just applying a etch primer to the bare metal?
It seems everything on this car is turning out to be not quite as bad as it looks, which is great.
Ok, found the epoxy primer, so I'll stick with the original plan. Epoxy followed by Urethane.
|01-31-2005 12:42 AM|
Good news! The major dents popped right up as you said they would! It looks like a different roof now, it is already a huge improvement although it seems there is still a lot of work to do before it's perfect.
I can't believe it freaked me out so much, I thought I was going to have to cut the whole roof out and strat from scratch!
I'll post some pictures for you as soon as I can download them off my camera.
I think the rest of the work that will be necessary is easily covered by your 'dent repair' guide, but I'll still keep you posted on how it's going.
|01-30-2005 08:54 AM|
Damn, you explain that stuff well Randy. I will be picturing those concepts each time I work with the stuff.
I know everyone doesn't need to know what is happening on a molecular level. But it really helps me understand how to make that metal do what I want looking at it as you just explained it.
|01-29-2005 11:59 PM|
Well, unless you are about to set up a shop in Cape Town, I won't be much competition to you and even if you did, I work in the film industry and I love it! So with me at least you are not working yourself out of a job.
Plus, you seem to me to be someone who loves what they do, just like I love telling stories through film, and the great thing about doing something you love, is that usually you become darned good at it.
There will always be others that are in it or come into a industry to make a quick buck, but the quality (or lack thereof) of the work will always show them up for what they are.
I know in my industry quality is about taking the time to craft something beautiful, putting something of yourself into every frame, every shot and often times you can't hope to recover all those hours when it comes time to invoice the client.
But, when all is said and done you know you have done a good job and that it is very likely that client will come back to you over and over again, and tell others about you.
I would much rather be known and remembered for what you pulled off on that Willy's roof, plus tooling up to offer replacement panels for others (any probably many more things I don't know about), than be making quick easy money by taking advantage of people that don't know any better.
Plus you are only 34 for crying out loud! When I began to read though your posts on this forum I thought you were easily in your fifties for some of the experience and wisdom that come across in what you write.
So I say more power to you! for whatever that's worth.
Okay, I'm done with my little spiel now.
I got to removing the seats, old carpets (what was left of them), headliner, and some other interior trim yesterday and I'll continue today, maybe trying to pursuade those dents to pop up.
I don't know if this will change anything, but there has been a interior fire at some point in the car, although the door panels are all still in one piece apart from melted armrests. I am not sure if the fire could have been hot enough to actually be the cause of the roof collapsing as it has, I doubt it, but if it had, would there not be some added complications?
I am not a metal expert (which is why I am writing to you) but I know that metal changes it's chemistry in certain ways when it gets hot and then cools, giving different properties depending on the rate at which it cooled down (and probably also how hot it got in the first place).
Hmm, but then again the vinyl headliner showed no signs of melting, so the roof couldn't have gotten all that hot.
I'll let you know if thosee dents come up as easily as you thought.
|01-29-2005 03:03 PM|
Hi Rich, (finally!! a guy who isn't afraid to use his real name)
I hope you do keep us posted of your progress. It's a great learning tool for us all. As more of you guys use the methods I constantly ramble on about, I think it will become apparent just how simple it really is. I just hope I don't talk my self out of a job!!!
Believe it or not, it's much easier to teach a guy who has never done any of this type of work before, because they are the ones who will actually pay close attention and follow every rule. I ran into the same problem teaching newbies in the body shop. The guys straight out of high scool with no formal training would hang on my every word and pick it right up, whereas the guys who had gone to "auto body school" THOUGHT they had all the answers and wouldn't listen to anything.
Male ego is our own worst enemy!!!
|01-29-2005 10:00 AM|
Thanks so much for your input, it wasn't too in depth at all. I want to know what's going on and the best way to fix it is to know exactly what is wrong with it in the first place.
I hope you don't mind if I keep you posted with how it's coming along. Some step by step help might be what's going to get it back in shape.
|01-28-2005 07:55 PM|
It looks bad..........BUT............I "think" it may not really be as bad as it appears. The first step would be to remove the headliner and evaluate the damage from inside. There's a good chance much of it will pop right up to where it belongs with a simple push from underneath. I wouldn't use a hammer to persuade it at this point, so don't get carried away!! Hammering on it will only worsen the condition, creating even more stretched metal and more work for you to repair. If you can't push it up by hand, you can use a porta power (if you have one) or simply use a bottle jack and a board. Something to help spread out the force over as large an area as possible would be a good plan as well. For the most part, what has happened, is the roof has been turned inside-out. There is n doubt some stretched metal as some point, but for now, let;s just concentrate on getting the bulk of it back to where it should be. Once it starts over center, it should pretty well pop right up to where it needs to be.
Getting into just a little metalshaping terminology here. Right now the shape (area) is correct, for the most part, but the form (arrangement) is way off. When shaping a piece of sheet metal, there are two basic things we read as the panel is shaped, that being area and arrangement. The area is the amount of stretch or shrinkage placed into the panel at the right spot to give it the desired final shape. The arrangement is simply bending and twisting it to the proper final form so that it takes on that desired look. This is what's going on with your panel.
The change in total surface area is only slightly compromised, meaning that it's not stretched all that much, however, the arrangement is WAY off.
To further explain this concept, let's take a shop rag for example. You can fold it, wad it, roll it etc., into about any form you want to put it in, but when you lay it out flat, it the same size it was when you started. You do this all day long, and there would be no change in the size of the shop rag. That's because you have done nothing to change the overall area of it.
Now, take that same shop rag and twist it as tight as you can, pull on it in several directions, tug on it for all you're worth!! Now what's happened??? When you lay it out flat again, it's larger than when you started. Why?? because the fibers have been stretched. The surface area has grown, rather than just being re-arranged!! The same happens with metal.
We all get a little freaked out over dents at times, but what it boils down to is learning how to read the metal, in order to tell it where to go. Overcoming the fear of failure is the #1 secret to success. You must always be in total control of the metal. YOU are it's master!! Never allow it to control you!!
Once you have the majority of the dents pushed up, I would suggest removing the rust. First you want to make sure the dents will come up as easily as I think they will before spending a lot of time removing rust. The rust will need to be removed before proceeding with the final dent repair though, as you don't want to hammer on rusty metal. It'll drive the rust into the good metal, making even deeper imperfections to deal with.
My apologies if I've gone deeper than you'd like, but I think it will help you understand it better once you really get going on it.
I'll need to look at the rockers and floorpans to give you sound advice on those. The floorpans and lower door skin should be fairly easy. I think the rockers shouldn't be too bad, but I haven't looked closely at one of these in a while.
|01-28-2005 12:33 AM|
|rlackey||Oops, seems I can only attach one file at a time. Here's the other one.|
|01-28-2005 12:32 AM|
Randy, here are a couple pictures of the roof damage. There are a few more pictures of the car as it is in my gallery.
Any suggestions you have would be very welcome.
|01-27-2005 07:53 AM|
Thanks for the explanation, I'll post some pictures just a soon as I figure out how.
The door jambs are actually in great shape, still have a decent coat of paint on them, so can probably get away without blasting at all.
Thanks again, I actually can't wait to get your advice on the roof, you are a very good authority to tell me if it's repairable or not as I actually may be making a mountain out of a molehill as such, just because I don't really know what can and can't be done.
Just something else quick, the only other damage I have to cut out and replace is the floorpan, both the rocker panels and the bottom door skin of the drivers side door (would be your passenger side I guess as this one is RHD), the other doors are very solid apart from the exterior surface rust.
As I don't have easy access to aftermarket replacement sheet metal in this country, will it be fairly easy for me to fabricate the floor, rocker panels and lower door skin from scratch?
I'll get those pictures up ASAP.
|01-27-2005 07:25 AM|
The pictures seem to be loading fine now. A little slow perhaps, but they are loading!! If you still can't get them, let me know and we'll work something out. It would be good if you could post pictures of your roof too.
As for the neval jelly, it's a mild phosphoric acid based rust remover in a "jelly" type substance, for lack of a better term.
It will stay on vertical panels and will also remain wetter longer than thin rust removers normally used. I've found that covering it with Saran Wrap, or whatever you have available as a thin plastic film, will also keep it wet longer, as it slows the evaporation rate.
I've used this trick for keeping paint stripper wet, so I tried it the other day with the naval jelly. It works!!
If you can't find the naval jelly there, get whatever type of rust remover you can and it will work. You may have to lay out a cloth on the surface and soak it with the product, but I imagine the plastic wrap would work on it as well. The trick is to keep the area wet at all times. Only work a small area at a time, rather than the entire panel, as this will help to keep it wet and it won't get away from you. Now, it's possible to work several panels at a time if you set up a production line.
Also, If the door jambs and such are rusted, you can get by with blasting those areas, just stay off the exterior body panels. You go around fender edges, trunk lid openings, etc. with the blaster. This will speed up the process.
Send us some pictures!!!
|01-27-2005 03:21 AM|
I just read though your guide on repairing the Willys roof! Amazing stuff but the pictures don't seem to show on the post now. Do you have it in some kind of document form or is there any way you could email it to me with the pictures if I give you my email address?
I have one heck of a job ahead of me on my roof!
|01-27-2005 02:20 AM|
Ok guys, I get the idea about the sandblasting, or any type of media blasting for that matter... ok on cast iron exhaust manifolds, not ok on sheet metal. I'm just glad I didn't do it yet!
These cars are not easy to come by in South Africa (even though they were manufactured here... mine is a RHD 4dr Bel Air built in Port Elizabeth), but reproduction sheet metal is impossible to come by without importing from the U.S. (at great expense).
Therefore I cannot afford to ruin anything on this body as it's the only one I have. This is also the problem with the roof, it is badly damaged, not just dented but creased in places right to the drip rail. It's a mess. I have no choice but to repair it... this is actually my biggest worry at the moment, but not the subject being discussed here, although I would appreciate anyone's advice. Anyone fabricated thier own replacement roof? I have another thread on this problem, see "Repair of large dents in roof?" (not sure how to include a link directly to another thread yet).
MartinSR, thanks for the link to the thread on rust removal, I had read that thread before posting but did not know the dangers associated with media blasting so still assumed it was quicker and easier. One question regarding the process described in this thread, and I hope it doesn't sound stupid, what is naval jelly? I have never heard of it here in South Africa, maybe we call it something else.
So in summarizing am I right in thinking my safe options are basically down to chemical stripping or good old sand paper and elbow grease (or a DA sander), and then as Randy suggested a couple coats of epoxy primer right on the bare metal, followed by a high build urethane primer.
This being the case, I have more time than money to put into this project anyway so elbow grease it is.
I actually apologize for bringing up this whole very tired subject that has probably been covered a zillion times, but I am grateful for your expertise, you guys may have saved my car.
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