I started to block sand the rear quarter panels. There where a few low areas on the panels that I was hoping the urethane primer would fill, probably more a case of wishful thinking. After blocking I realised that some of the areas where too deep for primer to fill without causing issue later.
These quarter panels are not as straight as I would like them to be. The first pair I fitted I used body filler to fill the low areas the same time I was filling the splice line.
The low areas are only minor so I decided to use a polyester spray filler, this is easier then trying to apply a skim coat of body filler. Seeing the quarter panels are polyester I sanded the urethane prime off and then sprayed the polyester filler. I believe it is ok to spray it over properly prepped urethane primer but I didn't want to chance it. The instruction say to spray it over epoxy primer (which for steel bodied cars is for adhesion and corrosion protection), I had already sprayed epoxy on the seams to seal the raw fibreglass on the original panels and the remaining areas of the quarter panels are polyester gel coat so there should be no adhesion problems.
I have never used this product before but now after using it I could not speak more highly of it. I wish I knew it was available years ago when I first started prepping the rest of the car for paint.
The polyester is very thick so I had to use a 2.5mm nozzle on my primer gun. Also once mixed you need to spray it straight away and then clean the gun out as it sets up quite fast.
I sprayed the quarter panels then guide coat and block sanded them. This showed there where still some low areas. Another coat of the polyester spray filler and blocking out with 320 grit, this sanded out the last of the guide coat just before breaking through to the gel coat.
The polyester sands very nicely and the best thing is there is no shrinkage, not like the urethane.
Now the panels are straight I sprayed them with tinted primer again. I will leave them for as long as possible before another round of block sanding and then paint.
The way this year is flying by it probably won't be until after Christmas before it's painted again.
The dark areas are low spots with guide coat still in them.
Another coat of polyester filler.
More guide coat then back to sanding. most of the filler will end up as dust on the floor (and everywhere else).
The quarter panel sanded. The white areas is the gel coat, I sanded as much of the polyester filler off as possible by removing all the guide coat and just stopped short of breaking through to the gel coat.
Back in primer again.
Dried leftover polyester in the mixing cup. This stuff sets up rock hard but has no shrinkage. The second picture is the dried product removed from the cup, it remained exactly the same size as the cup.
