body work for a newbie

[Mike K]

This is the book I found most handy //written in laymens language

http://www.bevenyoung.com.au/prdt502.htm

[Speedy]

thanks! I liked millers videos.
I made one fast because someone asked

http://www.youtube.com/watch?v=4Tw8oBdqm7s

I dont think any attempts will be taken today, busy

[Mike K]

Originally Posted by Speedy

thanks! I liked millers videos.
I made one fast because someone asked

http://www.youtube.com/watch?v=4Tw8oBdqm7s

I dont think any attempts will be taken today, busy

You are welding a row of individual tacks, rather than a long even bead ... Normally, the idea is to weld at least 1" long beads betwen the tacks before stopping . Distortion is always a problem with flat panels ... I guess your method does get around that problem nicely , but the downside is a bumby rough series of tacks instead of a long smooth bead

MIKE

[Speedy]

Originally Posted by Mike Kelly

You are welding a row of individual tacks, rather than a long even bead ... Normally, the idea is to weld at least 1" long beads betwen the tacks before stopping . Distortion is always a problem with flat panels ... I guess your method does get around that problem nicely , but the downside is a bumby rough series of tacks instead of a long smooth bead

MIKE

everyone on welding forums said the best way is to do small tacks.
I am going to try a small bead. still learning and practicing so I will try every thing.

I am liking the tacks. im guessing the bumpyness after grinding would be covered with body filler? (thats the next area I need help with)

so I did another attempt. this time I tried rotating the torch and took down my wire speed some.










only thing, it warps way to easy. I am thinking when I work on my jeep I will do some anchoring welds like that then turn it down some where I can control it easier.

im sure it would hold.

[hrpearce]

Try a run with a bigger gap between the plates it shoud improve your penentration and cut back on the height of the weld that needs grinding.

[Matthew Reid]

I'm No welder by any stretch but can stick stuff together with out it falling apart.

And everyone has their own method for doing light guage metal.
The trick is to find what works best for you.

For me the voltage your using is not near high enough and is leaving welds that are sticking up.

On your last photos your getting closer in a couple spots to full penetration as you can see on the back side where the gap has been welded closed. That is what you want to strive for.

Give this vidieo a look at.

http://www.youtube.com/watch?v=JohBH...eature=related


I use the same method for body panels and all light gauge metals. High heat short weld time with a cool down in between each spot weld and after few spots let the area cool to prevent warpage.
My machine does not have a weld time setting but you can do that on your own and after some practice you can get the spot welds all identical.

I personally prefer this method as pentration is guarenteed and it leaves a low weld that is easy to dress. Perfect for body panels.

While your waiting for the most recent welded area to cool you can spot up another location if the piece is large enough. If you want to speed up the proesses you can help speed the cooling with blast from your air compressor.
That will aso help from over heating and warping the surrounding metal.

This is not the fastest method to join light gauge metal, but if you have to dress the weld, the time is recovered in dressing out the welded areas and can usally be done with just a flapper wheel on a grinder. The bonus is it does not take huge amounts of skill to master this technique.

Matthew

[cantankrs]

Hi Michael,

I agree with Matthew except I gave up on the weld spot timer as I could wing it with less hassle. And hrpearce's bigger gap sounds right too. I've just checked what controls your Mig has in your earlier pic and I see your wirefeed was at that time set higher than your voltage. At those settings I normally would be doing continuous welds. If your welder dials do equate to mine (different brand) then for tacking I set the wirefeed rate just below the voltage rate (took me ages to work this out !@#$%^&)!! So set on '4' for voltage and just below 4 for wirefeed for single spot tacks. That has the heat high and the wirefeed slow to really fuse the tack with low buildup and maybe a little bulge on the back - but no gap still remaining at that spot. If you see gap still at the back then you're being too gentle and you have to find a closer compromise between tacking and melting through. If you're grinding flush (maybe you're removing a little too much I think and concaving the panel which means more body filler or spray putty) then in my opinion you want the back of your welds to be slightly bulged to provide strength. For thin stuff I never continuous welded longer than about 3/8" or I'd burn thru, or not penetrate, so good spotting was the go. And tacking at opposite places like tightening wheel nuts helps you keep progressing without stopping all the time to cool it (by force or naturally) - subject to patch size like Matthew says.

Also you might be able to squeeze a slight improvement (cos your pics are great) for us out of your pics if you wirebrush the soot off first. Would make it slightly easier to see and compare the tacks.

Regards

Alex

[Bob Carriere]

Nice job Stuart....... have you tried a copper backing plate to save on the grinding....?

Same process using the clamps but get a piece of copper from the scrap yard..... the heavier the better.... I have some 1/4 inch printing plates..... 3 by 7 from Cohen..... about $3.00 a pound..... brass blocks are also good and really absorb a lot of heat....

If you set up your copper plate behind the gap... held tight with clamps.... you could reduce you wire speed by 25% and your heat by 10%..... still get good penetration but much less grinding to be done on both side.

Have you tried the heat absorbing "gel" they sell for such butt welding..... said to be fantastic at soaking heat and reducing warpage......

Do you have to change your polarity on your Mig when you change over from .035 wire to .025....?

Boob

Bob C.