Bodywork

[tonkadoctor]

ALEX

Alex,

I approve of the method of laying the metal behind, (makes it easy to fill), but I strongly disagree with covering up the pinhole perforation as it will continue to rust and eventually bubble the body filler (moisture trapped in the rust causes this), sometimes in as little as a few months. Eventually you will have a leaky truck when it rains, I know this for a fact as I had an old '73 Gran Torino that I bought from a buddy of mine for $500. He had removed the vinal top and used about an estimated 5 Gallons of Bondo on the roof, I hated getting wet every time I drove in the rain, not to mention the fogged up windows because the car was always damp.

Welding and metal fabrication just takes practice, it is not something that you learn in a couple of hours and then are good at it.

Remember that you do have access to the shops at school and some experienced instructors to boot.

It all comes down to how long are you planning to keep this truck as to how much time you want to invest in the repair.

I am planning to keep mine for life and my metal repairs will be permanent like what Rick has done.

[RickL]

experiment

Alex,

For experience and learning you can always work on or make up some test pieces prior to welding on your truck. The morning I worked on my cab I spent about 10 minutes in the garage welding on some scrap 22 gauge sheet metal running beads and testing\adjusting my speed and feed. Also worked to get some nervousness out of my system prior to actually starting to weld.

I was just reading that Norm (New Yankee Workshop, This Old House, etc) builds 6 of each project prior to filming for his show. At that point its down to a pure mechanical action with no surprises. Other auto body sites have recommended picking up a scrap fender or hood and working on that to build familiarity.

One advantage of the M37 is it was built of heavier gauge steel then most of the newer vehicles.

Rick

[tonkadoctor]

22 ga vs WC-54 & M-37

Good point Rick,

Definatly use test pieces to set the welder up.

If you can weld 22 or 24 Gauge sheet metal together, You definatly can weld to the M-37 & WC-54 which are probably 18 to 20 gauge, (not sure yet because I havn't cut & measured it with my sheet metal gauge).

I will be using 16 gauge for patches and 1/8 diamond plate for the floors.

Rick,

After you grind the welds down use a little fiberglass gel resin with impregnated glass, like "tiger hair", to seal the patch before putting on any plastic filler. Just spread a thin layer over it and grind it back down.

You only need to do this over the welds to seal the pinholes and waterproof it.

Also consider getting a spray can of underbody coating and spray the inside of the cowl as it will hide the patch nicely, waterproof it and it can be painted over.

[RickL]

Thanks

Thanks for the tip. Actually the both the hood and the cab are thin metal. According to my sheet metal guage, the hood is 20 gauge and the cab area is 22 gauge. Might be a function of the need to make those curves and would have required heavier stamping if using thicker metal.


Rick

[RickL]

done

I finished welding in the patch today. Need to pick up some hearing protectors before starting to grind.

Do I grind the seams to slight depression or level with the rest of the sheet metal?

What should I do about the other side of the cab(reference page 1 for pics)

Thanks,
Rick

[tonkadoctor]

Cool

You just need to grind them at least flush but don't get too carried away or you'll cut through the weld.

Don't leave them high, its's better to be slightly lower to be able to fill it with plastic. Remember to use a fibergass resin product like tiger hair or duraglass to seal it from moisture coming through any pinholes or seams before you and lightweight filler.

After the coat of tiger hair is hard you can grind most of it back off as this stuff is really hard to sand, use the lightweight filler for shape.

For the warpage on the other side I would just hammer it to the best shape possible and then fill with thin layers of a high quality plastic filler, (NOT Bondo brand), that you can get at an autobody supply place.

[RickL]

TonkaDoc

Thank you for all your help. I will post progress photos as I go.

Thanks again,

Rick

[RickL]

update

I grinded down the welds and had to touch up a few spots but here is where I am at now.

[tonkadoctor]

Nice Work

That looks really good, definatly something to be proud of.

[RickL]

thanks

Is it normal to have some valleys and pinholes where the welds are? I thought that welds where supposed to grind out smooth with the rest of the area.

Rick

[tonkadoctor]

Imperfections are normal

Even the best welders in the world get imperfections and pinholes in their work.

The difference between body work and welding on nuclear steam piping is that you don't need to grind out the imperfection and weld it again.

Imperfections are caused by many things, contaminated metal, poor gas flow, dust etc....and the problem is compounded when you are tying in tacks as you have.

When you watch these shows like "American Chopper", "Biker Buildoff"........and you see them welding, If you pay attention you see that they only use the MIG welder for small tacks and when they weld it solid they always use TIG which produces alot cleaner weld because of the human control of the filler rod (with hands) and heat (with a foot pedal), it is also alot slower process.........What they don't show you is the entire day it takes to weld up a hand made fuel tank, the grinding of the welds, the checking for imperfections with inspection dyes, grinding out an imperfection and redoing those areas with imperfections and repeating this process as many time as is necessary for a near perfect weld.

NOTE: there is no such thing as a perfect weld all you can do is the best you can and rework an area when necessary which in your case is only if the weld cracks.

This is also the reason I suggest that you cover the area with "Tigerhair" or "Duraglass"......to fill imperfections and waterproof them before putting down a lightweight body filler.

[RickL]

THANKS

TONKADOC,

Thanks again for the advice. Not a big TV watcher usually either out in the garage or surfing the web posting questions reading articles.

Should those products be available at NAPA stores or do I need to find an auto body supplier?

Rick

[tonkadoctor]

Not Familiar w/ NAPA

I rarely go to NAPA but some of their stores do have autobody supplies and paint and should have a similar product if not those particular brands.

Any auto parts store that sells bodyshop supplies or a body shop supply store will carry similar products.

You'll only need a quart of the glass & resin gel it goes a long ways and will probably be enough for the whole truck as you make prograss, you only need one thin layer to seal and most of it will get ground off before you add filler on top to get it smooth. I would however get a gallon of a good quality plastic filler and a couple of 3" of 4" plastic spreaders.

P.S........Don't forget the tubes of activator for the resin & filler in your excitement when you go to the toy store.

Give me a hollar later this evening when I have more time to spend online and I'll try to teach you a couple of tricks for working the plastic & resin gel. gotta go for now as I am in the middle of moving and my buddy's on his way to tow my M37 to my new shop......woohoo...I'm entering the 19th century with an indoor workshop big enough to put a project in. (wasn't to happy with the house my wife moved into with NO garage while I was in Iraq...at least the landlord was pretty cool).

[RickL]

back from toy store

I stopped at a couple places and wound up getting the Napa\Martin Seyour Fibre Hair version of Tiger Hair, some Polyester Filler and some spreaders. I also picked up a can of 3M black rubberised undercoating.

The hardner came taped to the top of both cans so I should be good.

I should be online tonight but will probably skim on the first layer this afternoon.

Rick

[tonkadoctor]

Here's a tip for you

Here's a way to "Park" the spreader so it cleans off easily after use.

Simply take any excess to one end of your mixing board (whatever medium you are using) and make a nice pile of it at one end and then place the spreader in the pile and let the filler harden. You can then pluck it free and it will be clean of most residue and require minimal cleaning before the next use.

If you have one that already has chunks stuck all over it mix up a little and park the spreader and let it harden and then pluck it out. most of the chunks will stay in the filler and the spreader will be clean once again.