Cars: Rust and resprays

[udder 0]

Howdy all

Anybody have experience with panel beating?

Im looking at a bare metal job on my car which I fear contains a shitload of bog (body filler) I have some panels in the garage that im in the process of sanding back and priming. Both doors, bonnnet and front right panel to be replaced. Not to mention a new dash and re-trim of the interior. And im looking at getting a new roof and the section in front of the top door hinge is looking a bit rusty...

In light of all this I plan to strip it back and then take it to the panel beaters in primer with the new panels. Should I take it to them or is welding on new panels something within my reach? Im not great on a mig welder but can get by.

If I supply replacement panels which are free of rust, would this be cheaper than letting them repair current dodgy one?

Lastly, anoyone have their old car resprayed a couple years ago? WHats it look like now? Any rust spots returning?

understandable if I get no replies

"In one way or the other, I'm a bad brother. Word to the motherf**ker." Eazy-E

[AggieDave 6]

Quote

If I supply replacement panels which are free of rust, would this be cheaper than letting them repair current dodgy one?

*maybe* Just because its a new panel made for your car doesn't mean that it won't need any work and that it'll fit properly.

--"When I die, may I be surrounded by scattered chrome and burning gasoline."

[Scoop 0]

Hi, I'm a qualified panel beater although I've now left the profession.

Genuine (not pattern) replacement panels normally work out cheaper in the long run as there is less labour involved. Also you may find that if you keep the original panels you wont be offered any warranty.

If you leave rust on a panel it can be treated with a rust inhibitor but to be honest you'll never get rid of it fully (unless its just surface and your prepared to grind and sand it away. I would expect it to reappear in a few years.

Out of interest whats the need for the bare metal job? If you do that you really need to have the car finished and ready for primer in rapid time, matte rof days, else even the moisture in the atmosphere or from your skin will cause it to rust. If your happy there is no filler (use good old magnet) a well prepared paint surface isn't a problem.

If you still want to do it how will you go about it? Paint stripper is a pain in the arse and I don't recommend it, sandblasting is good but can distort panels and is very damaging around rust areas.

As for the panels, you can weld them on yourself if you know what your doing. Everything has to be immaculate (bare metal would be ideal for this) but ensure you use a weld through primer between any layers where the skins overlap. Panel alignment is crucial, especially if welding on a front panel.

A technique we used was a million pairs of mole grips and small self drilling/self tapping screws to hold the panels in place, then replace the headlights/radiator, bonnet, wings & doors etc. If it all fits nice, nice door gaps, nice wing to bonnet gaps, bonnet catch locks correctly then weld it.

The correct way (as approved by insurance companies and manufacturers) is with a number of spot welds and minimal mig welding. In a professional bodyshop, too many mig welds on a panel, or too many welds close together means removing the panel and fitting new one again.

If you need welding done to the roof or replacing a roofskin definately get a professional bodyshop to do it. Youll need to put the car on a jig to keep it stressed correctly as when you take the roof off it will want to fold up. I'd recommend the same if you are talking about replacing a pillar. The jigs used will hold the car in position and most have an integrated measuring sytem.

Also the heat from welding will distort the panel. Even heavy sanding or prolonged use of an random orbital (DA type) sander will cause distortion through that minimal heat as will the heat from the chemical reaction when filler is 'going off'

If you can get hold of a Thatcham vehicle panel guide that is invaluable although they are for trade only and you may have difficulty getting your hands on one.

Hope that helps, anymore questions, just ask. Ill try to help

EDIT TO ADD: If your welding is only to the standard where you can 'get by' I'd probably recommend not doing the frontpanel, pillar or roof yourself. Altogether, in the event of an accident, they are put under enormous stress and should work together to dissipate the energy of an impact. ie not snap or be rock solid because you've seam welded everything

[yardhippie 0]

Ive done a bit of bodywork over the years and let me tell you, its an artform. I aint no artist.
I spent months prepping a car to be sprayed.
body fillers, primers, sanding sanding and more sanding. to what I thought was a straight car. But, after it was painted, my skill level showed through.
Now if you add in the welding in poritons of panel and rust. WOW you have your hands full.
My experienced is that MIG welding is for attaching and strength, where brazing is used to fill and bond new with old. (neither of which I do well).
And to add with what dave said, you could get a brand new fender, bonnet, etc and it will need sanding, priming before the paint.

To sum up what i've learned:
You get what you pay for.
Good luck!

Goddam dirty hippies piss me off! ~GFD
"What do I get for closing your rig?" ~ me
"Anything you want." ~ female skydiver
Mohoso Rodriguez #865

[udder 0]

well there is definately filler . alot in the roof but it looks good and isn't bubbling on the roof. But there are numerous spots where the paint is bubbling and some rust showing. Id sand it back and lightly spray sections as theyre sanded back to stop rust. I have etching primer for this. Though I expect the paint shop will want to sand that back. It will be in primer for a few months though.

I decided bare metal because it really needs a thorough going over. Its a 1974 Celica and they aren't the best for resisting rust. And its not worth me selling it, so I'd rather keep it and slowly build it up. new panels arent really an option because of age. But I have a few off donor cars and am busy sourcing doors now.

thanks for the info about the roof. I had no idea it needed to be braced. There are sections of sill and small areas that I will weld myself but might leave larger sections to the panel beaters then.

and any take on electrode rust prevention systems? do they work?

"In one way or the other, I'm a bad brother. Word to the motherf**ker." Eazy-E

[Scoop 0]

NOTE

If your priming or painting wear an air fed mask, latex gloves, a suit and don't leave any skin exposed. Although your not exposed to it all day as your profession the chemicals in paint are poisonous and contain a type of Cyanide. It will pass through skin, not just through inhalation

NOTE 2

Wear a mask and use extration when rubbing filler or old paintwork ESPECIALLY IF HAS LEAD FILLER. Not only will it be more pleasant and less messy but the dust cannot be fully broken down by your body if inhaled so will remain in your lungs

[Scoop 0]

OK cool, sounds like a fun project if you got the space. Leaving the panels in etch primer is a good idea but etch is designed as a very thin layer, it is really a non sand primer. When used in the paint booth it is applied very quickly and you should be able to see through it, we (differnet companies have different guidelines) used to then apply a 2k primer over the top of it. However you need to lay alot of etch on to prevent corrosion. Do it, but build up in lots of slow layers, be patient. If you load on etch primer (which is very thin anyway) it will run all over the place.

Slow smooth movements with the gun is best, just lift off the trigger slightly at the end of your motions to prevent a build up of paint/primer at the end of the fan as else you would effectively be painting that part twice.

As for electrode rust prevention, I've really not had any dealings with them to be honest.

Theres no reason why it shouldn't be a good project if your patient and work methodically.

I've had lots of people deliver cars to us where they say "I've done all this" then I go and get a sander and remove all their hard work.

ANOTHER USEFUL NOTE: Do not use silicon based products where you are undertaking bodywork. I twill blemish the paintwork and its a fucker to remove once you got it. No matter how much you clean a panel with panel wipe, you won't see it until its painted. Where it'll appear a a white or colourless little speck. You might think its just abit of shit in the paint at first and try to buff it out, but its actually an area of no colour

Also if you do use primer, try and keep the storage area free of moisture and definately don't allow the car to come into contact with water or rain. Primer is pourous and will absorb the water, then leak when the car is baked in the oven.

[udder 0]

what should I cover areas I've repaired with if I want to drive the car around? I was under the impression I could drive around with a coat or regular primer over some etch primer?

"In one way or the other, I'm a bad brother. Word to the motherf**ker." Eazy-E

[Scoop 0]

Eww yuk, no way don't do that. The primer will act as a protective layer yes but it will get covered in road grime and will get wet. When you take it to the bodyshop they will sigh then remove all the primer and start again probably interfering with your repairs and have to rectify them adding yet more labour. Is there no way you can keep it off the road?

[udder 0]

well im happy resanding it, but just to make sure that it stops the rust? Thanks for all the help. Im off to bed. I'll PM tomorrow.

"In one way or the other, I'm a bad brother. Word to the motherf**ker." Eazy-E

[Scoop 0]

No probs. I've seen people spray some shitty layer of cheapo paint over the panel when they've finished it. They may be your best bet if you know its going to be some time before you'll get the whole thing done. At least then its waterproof and with any luck all you'll need to do is block the panel with a bit of 320, finishing in 500 grit paper. Then bit of non-sand and paint.... but its harder than it sounds

You may find this website useful for preperation info. The standard of the workmanship looks OK, not brilliant, but its a good guide as to how far back you need to take the bare metal areas compared to the size of the repair: http://www.jackspaintplace.com/coppermine/displayimage.php?album=lastup&cat=2&pos=5