117 replies to this topic

[Covert]

Hi Andrew, thanks for your help.

I see what you mean about the lack of penetration, stands out like dogs balls now that you've mentioned it . I'll try increasing the amps a bit and when I think back the wire speed did seem a little fast.

I might cut the patch out and have another crack with your advice on board before moving onto the outer panels.

Cheers

G'day Mav,
 
You can see from your 4th photo (looking at the other side of the weld) that you aren't getting very good penetration. You can still clearly see a gap between the two panels meaning that the weld is just 'covering' the join, so when you grind it flat you're exposing the join again, hence the pinholes.
 
Looks like you need to increase the amps and maybe decrease the wire speed, generally speaking you want to use the maximum amps you can get away with without blowing too many holes. If you're not blowing any holes in the panel then it's likely the amps are set too low.
 
With the wire speed, you want to use the lowest setting you can get away with without the weld stopping and starting, the less wire you add the better (and the less grinding you'll have to do later).
 
If you're welding a nice thick piece of new steel to a thin old rusty bit, you'll find that the rusty bit will burn away before you can get a decent weld into it, normally I'd say that in this case you maybe should've removed more of the rusty panel and installed a bigger patch, but that's not always possible so what you can do instead is adjust the sideways angle of the welding torch to direct more heat into the thicker metal.
 
Also, try not to do long continuous welds or you'll end up with warped panels, it's maybe not so bad with this panel because the pressings brace it somewhat but once you get into big flat sections of bodywork you need to be extra careful. Once tacked in, just do something like a 20mm weld, then move to another side of the patch and do another 20mm weld and so on until all your 'stitches' join up.
 
Have a look at the back of the weld (easily accessible here) to check your penetration, you should see that molten metal has completely filled the gap and probably needs a touch-up with the grinder on this side as well.
 
Lastly, throw a straight-edge (ie a steel ruler) across the inside of this repair when you're done to make sure it's flat in both directions, I reckon you might have trouble with the bonnet hinge binding if it isn't?

[Bigfella237]

No worries Mav, happy to help where I can, I'm certainly no expert but I've done my fair share of rust repair work!

 

I wouldn't worry about cutting that panel back out, just give it another squirt from the other side and have a play around with the amps and wire speed.

 

As I said, the highest amp setting you can get away with the better, just crank it up till you start blowing holes then back it down a little.

 

Also, the lower the wire speed the flatter the weld will lay down and the less grinding you'll have to do. If you listen to the weld it normally spatters more if the wire speed is too high, or the arc will stop and start if it's too low.

 

The worst you'll have to do is cut it back out and re-do it, but you were gonna do that anyway so have at it!

[hawk]

Had the same problem when I did the hinge repair. I just welded it from the back with slightly different settings and got some better welds. Keep up the good work.

[Covert]

Thanks guys, I welded up the other side today and although still not perfect I think it's a pass.

Anyway it's all experience

[Covert]

I have discovered an easy way of removing unwanted trim knobs

 

 

Attach a pair of vice grips tightly to knob, parallel to the pannel and rotate slowly untill the little bugger pops off

 

 

easy

 

 

Just need to put a bit of weld (some resulted in a small hole) in its place and will sand back flush

 

[Bigfella237]

Yes but has anyone found a way to put 'em back on?

 

Saw your photo in the random picture thread Mav, that weld was looking really good... right up until it had a blowout!

 

 

Notice how flat the weld is (meaning almost no grinding) and I reckon it'd look almost identical from the other side too (meaning good penetration).

 

I think you're close, either one click down on the amps or if you have a lump of scrap copper or aluminium to hold against the other side as you're welding, that will act as a heatsink meaning you can get away with the amps being set a little too high.

 

The only other thing is, they say you're supposed to have a slight gap between the panels if MIG welding a butt join, like about 1mm. You can butt them right up like that If using a TIG welder and just use almost no filler rod but that's not possible with a MIG because the filler wire is what conducts the electricity for the arc.

 

Practice, practice, practice!

[Covert]

Thanks mate, found this pic on the net and liked the look of it , I've had a couple of similar blowouts though, I've got a piece of brass in the shed will this work as well as copper?

Yes but has anyone found a way to put 'em back on?

Saw your photo in the random picture thread Mav, that weld was looking really good... right up until it had a blowout

Edited by Covert, 17 February 2015 - 05:11 PM.

[Bigfella237]

Not sure but I reckon brass will have too low a melting point so probably not? You're looking for something that conducts heat well, has a reasonably high melting point and won't weld itself to the back of the steel.

 

I wouldn't worry too much about it, a lot of places you can't get behind anyway.

[Covert]

Thanks victor, Im gonna fire the welder up again this weekend and get some more welding time under my belt

[76lxhatch]

I've had a couple of similar blowouts though, I've got a piece of brass in the shed will this work as well as copper?

A thicker piece of aluminium is an option, it doesn't last so long but has similar ability to draw heat and won't stick

[Covert]

Ok, I've been practising my welding this weekend and I've learnt a few things

1: welder settings are a lot less forgiving when it comes to 1mm panel steel (practice on scrap)

2: patience is extremely important, if you rush it you will frOck it up (take your time)

3: beer is mandatory for the armature welder (enjoy)

[Covert]

Picked up my rotisserie this week from the warehouse. If anyone has bought one of the blue and yellow ones of ebay this is where it comes from.

 

Fella in the forklift said this was about ten weeks worth of stock. The stack of crates was 5 deep.

 

 

 

 

 

 

[Bigfella237]

Who would'a thought so many people would be buying rotisseries?

 

Can't wait to see it set up Mav, I was thinking of building my own but after your post I had a look on eBay and was surprised how cheap they are, it's hardly worth the trouble of home-brewing one.

 

Although there's obviously still some custom mounts that need to be fabbed-up, but most people seem to use an old set of bumper brackets and weld them to the arms?

[Covert]

For the price of the steel and the time factor it's a good option I think.

I've been watching them for a while and got one for a good price, Also being local and not having to pay freight = a few more dollars for the build.

Finished putting it together this morning. I think your on to something with the bumper brackets, I'll see if I can incorporate them somehow

Cheers

[Covert]

Mounted the shell this weekend. Used front bumper brackets for front end and made some for the rear.

Can see the car at a whole number of different angles now.

Got some Sipping and staring to do while I decide what area of the shell to tackle next

[Bigfella237]

Looking good Mav,

 

I've always wondered how much extra the body flexes when you pick it up at each end rather than where the suspension mounts, but I guess it wouldn't be much with just being bare shell like that?

 

How would you rate the rotisserie you bought, did everything go together as advertised, does it seem sturdy, any extra features you wish it had?

[Covert]

No worries Andrew, didn't notice any flex in the shell, all went up pretty ridgid, you could probably do it from suspension points but would take more elaborate mounts.

Overall I'm happy with the quality of the rotisserie, it just took me a while to get one because some were buying them for $50-$150 more than I did, however patience paid off in the end.

Both ends have position locking pins which is good and pretty easy to put together even though all the instructions consisted of was an exploded view.

Major downside for me is that none of the wheels have locks. When I rotate the shell the rotisserie wants to wonder a bit which isn't ideal in a confined space like mine.

Apart from that it's all good

[SHEEL]

Just going back to the welding topic... on the previous page BigFella mentioned when welding patches into big flat panels, to only work 20mm at a time to avoid too much heat getting into the panel.

 

In my experience this is still way too much. I have found it best to basically never do a constant weld. The whole replacement patch is effectively tacked in.

 

for example on this section I repaired:

 

 

If you think of the round section as a clock face, I placed tack welds at 12, 6, 3 and 9 oclock.

 

then I waited 2-3 minutes for the panel to cool, then paced tacks at 1, 7, 10, 4 waited 3 mins, then tacked 2, 8, 5, 11.

 

then I did a tack overlaid/next to the right side of every existing tack around the circle. but only ever 4-6 tacks at a time, waiting 2-3 minutes between each round of tacks, and even wiping the panel down with a cold wet rag to cool it off...

 

it took me about 2 hours to finish the panel.

 

I also took the same appraoch when grinding/sanding the welds flat. only doing small bits at a time to avoid any heat in the panel.

 

you should pretty much be able to hold your hand on the panel all the time, you want to ensure it NEVER gets hot.

 

when I finished this panel, I required probably less than 1mm of filler around the welded in section. It is very close to having practically no filler. There is no warping.

 

In my mind you are far better off to spend 3 hours welding slowly than 3 hours or even longer trying to fix a warped panel! 

[Bigfella237]

In my own defense, I recall we were talking about welding up the bonnet hinge area, not that it matters.

 

I really think you're being way over-cautious with what you describe above though, but to each his own, if you can afford to take 3 hours to do a 5 minute job then more power to ya, but I guarantee any panel beater that did that wouldn't be in business long!

[SHEEL]

Yeh absolutly for the hinge area or other small panels you can just go for it... no problems.

 

An experienced panel beater can actually use heat to shrink and expand panels, so even if they do warp a panel, they can shrink it back. 

 

I wish I was that good!

 

I think for a novice it's better to be overly cautious to avoid warping. If it takes a few hours to do the job once, rather than having to spend even more time re-doing it... thats time well spent I reckon.

 

I am overly cautious for sure... but no harm in being that way I think.

[Covert]

Thanks Daniel, I'm beeing pretty cautious aswell as I've learnt not to underestimate just how fast pannel steel can heat up, one tack or bead too many and you've got problems.

 

Ive found a few good videos online where the pros show how they do it. They seem to be able to move a bit faster and still get good results but I guess that all comes with experience.  

[Covert]

Ive deciced to start work on the boot floor next.

 

The wire wheel revealed more holes than I originally thought were there which is not suprising really.  

 

I'm gonna tackle it in sections rather try and replace the whole floor as there is still plenty of good metal amoungst the rot. 

 

First section is the passenger side.

 

 

 

 

 

Not sure if I'm going to have a boot mat yet or not but either way I want the floor channels to look legit.  

 

After bashing the original flat and some measuring I put a new channel in the patch with 3 bends and some minor dolly work

 

Bend 1

 

Bend 2

 

Bend 3 and we have a nice channel which is pretty much spot on in size with the original

 

Just need to cut the patch to shape and fit this weekend (hopefully)

[Bigfella237]

Getting into it now Mav, does anyone make a full boot floor replacement panel? Or more accurately, does anyone make one that actually fits?

 

I know you said you didn't want to do the entire panel but sometimes it's still worth buying one to cut pieces out of, although I guess it depends which pieces you need, some of the more detailed stamped sections are hard to make yourself.

[Covert]

Rare spares do one including spare wheel well for $660. Not sure if anyone else does them.

Probably worth it if the whole lot needs replaced but a bit expensive for cutting bits out of I thought

I'm looking at getting the spare wheel well panel on its own though as mines rooted