So after what I have gleaned from here and VODC I decided to have a go at replacing my rotten drivers rear arch. Here's what I did.
^ My old arch. I've marked where I want to cut and started to cut along the top. I carried on grinding along this groove till it went through but apparently this isn't the best way to do it. According to my old man you should pierce it with the grinder then inch it along backwards and forwards making sure you're cutting in the waste. Apparently this gives you a straighter cut. The straighter this edge is the easier it will be to cut the other piece to fit.
^ Here's both holes cut out. I made the front one bigger so I could weld the inner piece on from the outside. The inner piece will be a lap joint so it doesn't matter how straight the edges are. In this pic it still needs a bit more grinding to get the edges to bright metal.
^ I cut the piece for the inner out of the waste on the repair panel making it plenty too big as the bottom needs folding over.
^ The inner panel on the car is doubled over at the bottom and then folded at a right angle. My Dad lending some expertise here to double the edge over on itself.
^ More
^ A bit more
After that I had to put about a 30 degree bend in the top.
^ Offering it up
After a bit of weld, not the neatest.
I had the welder set on half power and spotted all the way along as any more power or longer runs would burn though the metal. This time I learned how important it is to weld at the correct angle. Also, newspaper should have been replaced with a wet rag - a bit of a fire hazard there.
^ After a grinding down and some more welding. Covered it in underseal after a bit more tidying up.
^ Offering up the outside piece. Still too big which is good! As the top edge wasn't straight it was a bit difficult cutting the piece to fit. I just kept on grinding a tiny bit off till it fitted all the way round. Much harder than the inner piece as that was a lap weld whereas this is a butt joint all the way round.
^ Outside piece tacked on. I started with a tack in the middle as this is the hardest bit to move. Once the middle is on I tacked at the ends. Then I went along the top and pushed the metal where it was proud and tacked it in place. Fully tacked in place in this pic.
^ Action shot! Filling in the gaps between the tacks. I found a blast of about a second was enough to get a decent spot of weld on. Before doing this I had tacked the bottom edge on which is pretty awkward but nothing compared to inside the top of the front suspension turret
^ After some grinding.
^ You can see some gaps in the weld here. I went back and welded them and filled the gaps in the weld along the bottom edge.
^ All done and painted with some zinc primer. Unfortunately I did damage the paint above the trim line so I'll have spray that in. No problem though as I don't have lacquer
