Subject: [Shop-talk] Learning to weld on your own?

From: Darrell Walker <[email-masked]>
Date: Mon, 29 Jul 2013 15:54:43 -0700

I have some body repairs I'd like to do on my TR8, and I'm wondering about the
feasibility of learning to weld well enough to do them on my own.  I've
checked the local community college, and the only welding classes they have
are geared toward students preparing for a career in welding, they don't have
any "Adult Ed" type classes.  Of course, I could have a body shop do it, but
the few that are willing to do this kind of work want to do the whole job at
once, and not piecemeal (I also want a respray at some point).

I have three different things to address:

1.  The car came with a bump strip along the sides, which I didn't care for.
It was attached with pop rivets, so I have a series of 1/8" holes along each
side, from the front fender, across the door, and across the rear fender.  I
have access to the back of most of the holes, but not all.  But I do think I
can spray cavity wax everyplace.  Right now the holes are covered with some
silver 3M striping tape, which is pretty invisible beyond about 10 feet.  But
it would be nice to get a more permanent solution.

2.  The car came with a luggage rack, which I also removed.  That left eight
holes from the sheet metal screws.  These are a bit larger than the pop rivet
holes, and of course distorted from the screws.  Half of them have easy access
to the back side, but the other half are hidden under the stiffening rails.
Again, I could certainly get cavity wax in there.  Right now I have some plain
aluminum plates screwed over where the brackets go (the car is silver).

3.  The last area is the rear panel.  The car was hit in the back at some
time, and wasn't repaired very well.  It looks like they made no attempt to
pull anything out, and just sculpted the area with Bondo.  It actually doesn't
look as bad as it sounds, except that the panel is pushed in about an inch.  I
think the best way to fix this would be to install a new panel, if I can get
one.  Also, some of the panels in the boot are crumpled, and those are
available.  These are all attached with spot welds.

So, my questions:

1.  Is it reasonable to think that I could teach myself to weld well enough to
do these jobs?  I definitely don't want to make anything worse in attempting
fix anything.

2.  What kind of equipment would be required?  Would one of the inexpensive
110V welders be sufficient?  Would a TIG matter over a flux wire-feed for
these jobs?

3.  How much paint should be removed around the repair holes?

Thanks!

--
Darrell Walker
66 TR4A IRS-SC CTC67956L
81 TR8 SATPZ458XBA406206
Vancouver, WA, USA
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From: Randall <[email-masked]>
Date: Wed, 31 Jul 2013 2:01:18 +0000

---- Darrell Walker <[email-masked]> wrote: 
> any "Adult Ed" type classes.

So?  They still teach you to weld, and surely you can manage to tolerate standing next to some pimply faced kid.  A friend of mine recently took some welding classes at our local community college, and he was very pleased.  I keep planning to take some myself, but there never seems to be enough time. (I actually kind of envy him getting laid off.) You might also try a vocational college, they get a lot of displaced workers looking for a new trade so you should fit right in.

> do these jobs?  I definitely don't want to make anything worse in attempting

I have dabbled some with teaching myself.  I believe it can be done, but you're talking about a lot of time and a lot of practice even after obtaining and reading some textbooks on the subject.  Run a bead, compare it to the book.  Repeat until you can consistently match the book.  Now cut it apart for inspection, adjust your technique for penetration, etc. and do it all again.  Now repeat the process, using metal and joints similar to what you want to do on the car.  Might want to visit the local junkyard for some car parts to cut apart (or drill) and weld back together.

Also poke around on YouTube; there are all sorts of "how to" videos.

> 110V welders be sufficient?

IMHO, although you might get away with 110v, you'll want one a better quality machine.  Those cheapies at HF are just junk.  Look for something with a contactor (so the torch is not electrically hot when the button isn't pressed) and the more current/voltage settings the better.  A good welder can adjust movement to match the machine, but I'm not that good.

>  Would a TIG matter over a flux wire-feed for
> these jobs?

Flux core makes an awful mess; IMO you shouldn't even consider it.  MIG is probably the best choice for sheet metal on a budget.  TIG is great, but the price of admission is significantly higher.

Another method that might be worth looking into (although it's much less popular) is torch brazing.  It's slower and more expensive, but IMO you are less likely to ruin your original sheet metal (since it doesn't get melted at all).  I don't claim to be good at it, but I can braze much better than I can stick weld.  And you can get started with just a MAPP gas torch and some rod.

> 3.  How much paint should be removed around the repair holes?

You'll need several inches, at least.  Remember the metal is heated to melting point where you are welding, so it's going to ruin the paint even outside the "heat affected zone".

--- Randall

[email-masked]