Thread: Need some advice on welding of car body panels.

I was at work today and had the camera in the car so took these photo's of a guard which hangs on the wall in the panel beating workshop. I thought those looking at this thread may be interested in them. This type of repair can't be done with a mig welder. Lucky for me I have always worked with trademen who excelled at this type of work, unfortunately its hard to find younger tradesmen who are really good at it and as governments have been steadly downsizing tafe colleges you can not easily get classes which teach such skills. 10 years ago anyone wanting to learn to restore a car could enrol in tafe, today virtually all such courses have disappeared.

The advice about oxy is spot on but as you have not exactly stated what the repair exactly is it's a bit hard to give more specific advice.

First thing is the welding of thin panels is a particular skill, so different that normal welding classes don't teach it. In the panel beating trade its taught as one of the first basic skills they need. A good student normally takes 3 to 6 months at tech before he finally gets the various techniques mastered well enough that his boss would let him attack asimple job on a customers car. Often some never get the hang of it properly and others you wouldn't let anywhere near a car.

Any decently trained panel beater would have no problem oxy welding any panel and getting a good result. Unfortunately time is often the main consideration and smash repairers are paid probably the worst hourly rate of any trade ( its only $30-$35 per hour) so usually its a rough beat out zap with a mig welder and plastered with plastic filler or easier still replace the panel. After a few years most tradesmen loose the skill enough that you get that blank look when you ask them to repair a panel properly.

If you know of anyone who is in a car club or has a restored car they probably know someone who is able to do such work. If this repair is not that big I would be making further enquiries before setting about tackling the job. If you don't get the techniques correct you may turn a fairly simple repair into a major stuff up which may not be easily fixed. If this is not possible then Grahame Collins advice about getting my old boss Don Wait's book is the way to go.

The photo's are of two front guards cut in half and welded together with oxy, they are file finished on the front. The back as you can see still shows the weld. The paint on the front and the proof coating on the back are removed well and truely away from the repair before it is welded. The student who did this would have received a mark in the high 80's. You can just see that some of the join is still visible after filing, done properly the join is invisible from the front and requires no more filling before the painter can respray it.

If we knew exactly what the repair was I'm sure we could give you some more specific advice.

Metal Head, exactly what is it about spot welding on a car you are enquiring about?

Unfortunately time is often the main consideration and smash repairers are paid probably the worst hourly rate of any trade (its only $30-$35 per hour)

You have obviously never worked in a factory durwood? As a qualified fitter & turner I have never earnt more that $25 an hour. So I wouldn't say that you are being hard done by in comparison to other trades people.

You can just see that some of the join is still visible after filing, done properly the join is invisible from the front and requires no more filling before the painter can respray it.

Did you mean "filling" as in filler compound or "filing" with a metal file?


Metal Head, exactly what is it about spot welding on a car you are enquiring about?

Like guards (known as wings in the UK) to the engine compartment, or new sills to the existing framework, or is spotwelding not used because it's welds aren't strong enough??

I've worked in lots of factories and for myself, What the actual worker gets is not the hourly rate. The boss has to pay your holidays, sick pay. compo plus all the business cost and more. I don't know of any tradesman who quotes less than $60 an hour costs that much for a washing machine mechanic, next door the neighbour has builders who are working on $70. If I get my car serviced they charge $65 and half the time its an apprentice who's doing the service work like changing oil.

I meant filing, the metal is welded, planished with a hammer and dolly and then a body file is used to smooth the surface. If there are highs or lows they are then brought up to level with the hammer and dolly or with a pick hammer to riase the area or heated up and shrunk to remove the stretched metal and the process is repeated until the metal is smooth and the desired shape. If you arn't good at this the answer is to use a plastic filler or lead to level the surface. but he ideal is smooth metal no highs and lows - invisible repair.

Spot welds are numerous on a car there are thousands of them. Depending on the design they may or not be used in certain places. A lot of cars don't spot weld the front guards onto the skirts so thay can be easily replaced. The repairer has a choise of methods for original spot weld parts. He can use a mig, plug weld or spot weld or oxy weld depending on the circumstances.

On a lot of the new cars the steel used is special high strenght and you have to spot weld ( or use specified welding) or the repair is not safe.

Thanks for the comments guys. This info is invaluable. Grahame, I'd like to know more about that joggle joint. Is it like the side seams on my Levi's jeans? The bottom of my door will be OK. This little ute has never been near the coast. Came from out at Winton in central QLD. Where did you buy your zinc anneal sheet from? I'm definitely getting Donald Waits books (asked Mum and Dad for Xmas, hehe).

Originally Posted by durwood

I've worked in lots of factories and for myself, What the actual worker gets is not the hourly rate. The boss has to pay your holidays, sick pay. compo plus all the business cost and more. I don't know of any tradesman who quotes less than $60 an hour costs that much for a washing machine mechanic, next door the neighbour has builders who are working on $70. If I get my car serviced they charge $65 and half the time its an apprentice who's doing the service work like changing oil.

I meant filing, the metal is welded, planished with a hammer and dolly and then a body file is used to smooth the surface. If there are highs or lows they are then brought up to level with the hammer and dolly or with a pick hammer to riase the area or heated up and shrunk to remove the stretched metal and the process is repeated until the metal is smooth and the desired shape. If you arn't good at this the answer is to use a plastic filler or lead to level the surface. but he ideal is smooth metal no highs and lows - invisible repair.

Spot welds are numerous on a car there are thousands of them. Depending on the design they may or not be used in certain places. A lot of cars don't spot weld the front guards onto the skirts so thay can be easily replaced. The repairer has a choise of methods for original spot weld parts. He can use a mig, plug weld or spot weld or oxy weld depending on the circumstances.

On a lot of the new cars the steel used is special high strenght and you have to spot weld ( or use specified welding) or the repair is not safe.

Thanks for the reply Durwood.

Oxy eh. I thought TIG would've been the process of choice.
Well, you learn something everyday

Hi Jim
what you are after is a Panel Flanging Tool

http://www.totaltools.com.au/downloa...tool_23_24.pdf

or as a manual type
see photo below.

Your ute will have no tricky alloys to weld.

What other correspondents refer to are what I know as HSLA High strength low alloys.The reason for many new vehicles being able to acheive better fuel economies is that.
the steel is thinner ,weighs less than equivalent thickness in the old type steel but is much stronger than the old stuff.

As for zinc anneal sheets see your local sheet metalworks who will advise you on the correct thickness .I think it is around .6mm thick from memory.

Don't be afraid to get some old scrap panel OLD panel not HSLA panels and have a good practice before you even touch the old ute.

Cheers for now
Grahame

hey Grahame

On that tool sheet I see a couple of mini-hacksaws. This is exactly the thing I will require for my cutting out of the damaged area. I am aiming to do a really fine cut so there is minimal gap when I weld the panel back in. Thanks, where do you get those tools? I assume I can find it from their web page? Yes - there is one handy in Brisbane.

I reckon that HSLA is what I would have called "high strength quenched and tempered low carbon steel". But, usually called Bisalloy. I have welding specs for that but understandably the strength properties are lost once it has been heated up above 800 degC. Hopefully this won't be something I come up against. It's a good idea to get some old panel to practice. I'm going to make some strips up as backing bar for my welds too, I think.

hi Folks

Here's the photo of my door damage. Looks bad but is localised. Hinge area is bent back but I believe workable. Frame on the car body side seems fine, luckily. By cutting out the skin damage I gain access to work on the hinge area from both sides too. I'm thinking of tek-screwing the door to a wood pallet once I get it off, then I can hold it with my boot while I apply some force on the hinge area.

Hi jim
I thought you had a rusty door base.My advice on cutting was based around that premise. the picture is worth a thousand words. Maybe you won't need those toys.
The repair now does not look all that daunting.If there's not much damage to the door frame, I would consider pulling that damage out with a slide hammer. The majority of the work is done with the slide hammer and the rest with a dolly and slapper.
I would leave the door frame intact,to start with, so it can resist the force being applied to the skin.
It appears to be damage caused by reversing with an open door and catching a post - gateway was it?

Its just me, but I think you could get away without the need to cut a piece out of the panel. But I don't claim to a panel beater.What say the real panel beaters ?

Its sounds like from your comments about Bisalloy that you are a metal fabricator .If thats the case you can save a quid and even make the slide hammer. Save a few dollars.

Grahame

As Grahame said you don't need to do any cutting just lots of pulling and hammering plus some shrinking, as said previously go and buy Don wait's book this book is the BIBLE for beginners

Yep No welding needed there, wish we had a picture (as Graheme said - worth a thousand words) would have saved a lot of posts.

No welding just pulling back to original shape and repairing the damage but you will need a lot more force than your boot can exert. A panel Beater uses one of several hydraulic ram devices to do a job like this clamp onto the back edge of the door grab the damaged edge and pull it back then repair any frame and skin damage left.

Get Don's book or another door.

quickest is to deskin the door and work the hinge area as well as the brace the door is buckled to half way along and bent at the top also the hinges will possibly be out of shape as well. Then the top window frame will need to be checked.

If you can get a hold of a ram puller or even a small bottle jack using oxy to heat/warm the areas you'll straighten that out no worries it ill take time for a beginner.

Remove the window winder and glass

Oh and dont be surprised if the door pillar is out of wack a little

I did my TAFE course with Donald Waits SIL he was head teacher back in the 70's.

Well guys, the panel beaters wouldn't touch it! I was shocked, as you can see, the damage is not a big deal. Last thing I expected was to have to do the job myself. I'm really looking forward to it though, because I have fixed just about everything that moves in my life, thanks to all my Dad taught me, but I've never done panel beating or car restoration. Who knows where this will take me.

BTW I actually did the damage by letting the vehicle roll away. Sadly the rear end is damaged too but we will discuss that another time. The door is the main dilemma.

I am somewhat shocked by the guys that are suggesting the panel can be fixed without removal from the door. Consider this, by cutting that piece out I figure it will be a cinch to just hammer out the ding. Then the bonus is, that while the piece is cut out I can also work the area near the hinges. I reckon it'll be a little bit tricky to cut out the spot welds along the front of the skin before I can remove the cut piece.