Dude you will find your welding improve ten fold if you remove all the paint and crap.
Its looking good but you reely do need to get down to nice shinny bare metal.
Looks like Zintec to me not Galv, zintec's great for car repairs as long as you clean the zinc off the edges your going to weld,also good for storage as it doesn't rust ( only maybe any cut edges ).
Dont mean to hurt your feelings mate but those welds look ****e !
Migmag i was going to say it would be easier if all the paint was removed. To be honest the best way i have found on cars (and i hate welding cars, and try not to do it) is a grinder with a wire brush, less abusive than a grinding wheel and removes the paint nice and easy leaving it clean.
I would think for you guys that work on cars these would be cool
Basically bits of emery cloth stuck to a grinding disk, available in 40,60,80 and 120 grit, far less abusive than a grinding disk, redhot for polishing down a weld to a nice smooth finish. Great for pre-cleaning when welding dirty steel, I use them for splatter removal when i make railings, zap them all over the railing quick, knock of sharp edge and paint for a perfect finish. They normally cost about £2.00 ish depends on the quantity you buy, I get mine from my local welding distrubuter.
Pic isnt great but gives you an idea of what they are like
I normally use the stainless steel wire wheels on the grinder, they last long, seem a little more course, and the very next time you use them they aren't covered in rust, but they are over twice the price.
Arc welding is reasonably forgiving when it comes to dirty metal, mig lets you get away with a little surface rust no problems, and tig well if you cant see your face shining back then it aint clean enough.
Problem is with miging up cars is any paint will act as an insulator, thus it wont arc and you end up with the famous pigeon poo type welds, and loads of splatter. The undoubted best method for cleaning up in my mind is one of the small type grit blasting units, with a good air supply anything left after 5-10 mins of blasting is good weldable metal anything missing, well it would have needed welding sooner or later, thing is most people are working to a budget, and the extra cost just isnt needed
I do agree the problem is not cleaning the area's to be welded but perhaps SIP130T would be well advised to study Malcolm's project pages and have a good understanding of how good welds look and are attained, then work on scrap material ( even the metal you cut out of the project car as long as you have cut back to some decent stuff ) then when you have experimented with machine settings and have made some good welds with good penetration have a practise on the project vehicle leaving structural parts like chassis legs etc until you are 100% confident of making a good weld.
Its his welding that needs attention which I advised him on.
encouragement,guidance and compliments where appropriate are far better that simply calling his work [poor]