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Re: Wot, not another '79 Targa resto thread

Posted: Tue Nov 07, 2017 6:36 pm
by defianty
PeterK wrote:Only worry is that by the time I get to the end, will I feel the need to redo what I did at the start :lol:
:lol: I've already done that! If you truly know it's not good enough then it's not time wasted doing it again.

Re: Wot, not another '79 Targa resto thread

Posted: Tue Nov 07, 2017 8:55 pm
by 911hillclimber
There, wasn't so bad was it! :)

Skills sure improve over the resto duration, we have all had that feeling..
Try painting the car yourself and it can really show.
Press on, looking good.
Going to the show myself to boost my mojo.

Re: Wot, not another '79 Targa resto thread

Posted: Tue Nov 07, 2017 10:48 pm
by Dougieboy1
'not happy wth the penetration.....' - story of my life.

your welding is fine, its your painting you need to sort out!

Re: Wot, not another '79 Targa resto thread

Posted: Wed Nov 08, 2017 4:08 am
by jjeffries
I'd suggest not priming the exterior surfaces of your work until after the welding and grinding is complete....I understand coating the soon-to-be unreachable inside bits, but other than that you're making life more difficult than necessary. Put down that brush!
Re: the gentleman who said he didn't he does everything except weld, i'd say to give it a try. I think the lesson we all learn is that MIG welding can be learned quite quickly, but it's the associated skill of forming the replacement metal that is truly humbling and makes us all ooh and ahh over Barry Carter's work, or that of the lovely old blokes at Chesterton. Just as I recommend this forum to anyone doing 911 metal work, so too do I find abcgt.com fascinating. That's an American site, very low key and not the slightest bit a-holey, all about 356 projects. As with Barry here, there are some pro's who comment and add incredible wisdom. Best to all, John

Re: Wot, not another '79 Targa resto thread

Posted: Thu Nov 09, 2017 6:03 am
by sladey
On your welds - you mentioned running a bead. I found it much easier with thin panels to pulse-weld - so I do one strong spot-weld/tack, and then do another overlapping it a bit/or right next to it - and carry on I find the pause in between stops me from rushing, ther fact I’m continually re-placing the next weld stops me from going off-line. You get a natural rhythm of going it after a while and the previous spot is still red-hot when you do the next one - so you end up with a strong, reasonable-looking weld.

I found when trying to run a bead on thinner panels I couldn’t judge the speed properly so sometimes ended up with snot sitting proud, and more often than not I’d end up going off line

HTH and keep it up

Re: Wot, not another '79 Targa resto thread

Posted: Thu Nov 09, 2017 7:44 am
by PeterK
Thanks Mark. My first weld attempt (lacking penetration) was a series of spot welds as you suggest. It was the redo where I ran the series of short beads - probably a combination of frustration at this point, and not wanting to risk cool spot welds sitting on top of the previous. Must think more and rush less :oops:

Re: Wot, not another '79 Targa resto thread

Posted: Thu Nov 09, 2017 10:27 am
by sladey
The spot welds are good because you can crank up the power a bit so get good penetration but because you pause after each one less likely to blow holes

Re: Wot, not another '79 Targa resto thread

Posted: Thu Nov 09, 2017 10:28 am
by sladey
What welder do you have?

Re: Wot, not another '79 Targa resto thread

Posted: Thu Nov 09, 2017 10:30 am
by sladey
I used to have a SIP hobbyist one and it wasn’t easy to get consistent results. Spent more on a portamig one and it’s a world of difference.

A good welder (person) can make any welder (machine) sing; a bodger like myself needs all the help you can get

Re: Wot, not another '79 Targa resto thread

Posted: Thu Nov 09, 2017 1:29 pm
by PeterK
A few months ago I sold my Clarke and bought a Portamig 185 - your fault :lol:

My (one of many) schollboy error was not cranking up the volts for the spot welds. I was only using setting 2 (test welded some scrap metal before) - 3 seems better in the real world

Re: Wot, not another '79 Targa resto thread

Posted: Thu Nov 09, 2017 1:42 pm
by sladey
Ha! Glad you've got a proper one

I think I'm generally 5 or 6 on the low setting for the spot welds - but experimentation is the key

Re: Wot, not another '79 Targa resto thread

Posted: Thu Nov 09, 2017 2:49 pm
by 911hillclimber
I have a SIP and it is really hard to do these sheet metal welds. If I did more bodywork nowadays then I would upgrade.

I've taken to a spot every 10mm or so, then go between them, and then between THEM and so on until all joined up.
I have NEVER been able to make a weld and not have the wire feed carry-on after trigger release so needing a 10mm snip after every weld, spot or run. Drives me mad.

One day I'll bite the bullet and get one like Barry's as his welds are perfect, must be all down to the machine, right? :)

Re: Wot, not another '79 Targa resto thread

Posted: Thu Nov 09, 2017 2:53 pm
by Gary71
I know myself and sladey always preach it but once you have a Portamig then any crap welding is entirely your fault!

Re: Wot, not another '79 Targa resto thread

Posted: Thu Nov 09, 2017 4:25 pm
by PeterK
I know it’s not the welding machine’s fault in my case :lol:

It’s easy to teach yourself to weld poorly, even after help from youtube !. I learned gas welding donkey’s years ago and then a couple of years back found it easy to stick metal together with the MIG, but not really quality welds. Buying a rusty 911 is probably neither the quickest nor cheapest way to learn, but it is certainly a fun way !

Always appreciate hints & tips (& any suggested settings). When the Portamig arrived I tried a variety of settings using steel offcuts but real life tends to need additional heat. Nice to know what others have success with.

Re: Wot, not another '79 Targa resto thread

Posted: Thu Nov 09, 2017 5:51 pm
by Gary71
I’m no expert, but biggest issue I can see is you are trying to weld big gaps through paint in a continuous seam.

As Sladey said, on thin stuff you can ‘pulse’ the trigger creating sequential big tacks joined together. Helps keep a straight line.

I use a spray on weld through primer on overlapping seams. Butt welds should be bright shiny steel 20mm either side of the joint.