Thursday, March 10, 2016

I heart bondo

Seriously, at this rate I'll have the car out again before I'm done posting all the stuff I did last fall...  With the hood fiberglass done, it's time for bondo.  I've already posted why Bondo brand bondo is terrible and should be avoided at all costs.  My biggest complaints are that it spreads poorly, and sands hard.  I mean, it works, but you end up using more effort and going through more sandpaper than with other fillers.  There are much, much better products for not a whole lot more money.  My filler of choice is Evercoat Rage Gold.  It's about $20 more per gallon than Bondo, but the time and sandpaper it saves are well worth it.  Concidering the $800 I'm likely to spend on just primer, paint, and clear, an extra $20/gallon for filler is nothing.

The first thing I did was sand down all the fiberglass with 80 grit sandpaper.  All the 'glass was sanded close to the final panel height, and all the left over paint was removed from the repair area.  Then I mixed up a big batch of bondo and covered the whole area in one go.  The big blue tarp not only helps keep the dust out of the engine compartment, it also catches drips in the bondo.

If you catch the filler at just the right point while it's hardening, you can remove a whole lot of material very quickly.  Using my longest sanding block and 80 grit paper, I sanded the whole area down.  You want to use the longest sanding block you can because you'll end up with a flatter result.  NEVER use power tools for your final filler work.  If you do bodywork all day every day, you're probably good enough to get away with it, but if you're inexperienced, power sanders will leave you with a very wavy surface.  It quickly becomes apparent when sanding where the highs and lows are.  The highs get sanded down some more, and the lows get more filler.  Ideally, you want no more than 1/8" of filler thickness, any deeper than that could conceivably crack(though that's unlikely) and should be filled with fiberglass instead.  Pinholes in the fiberglass should be ground out too, to avoid problems down the road.

You'll notice that I bondoed right over the edge of the hood scoop hole too.  Since much of that area is new too, it also needed some work.  With the scoop as a guide, I used my die grinder, some square files, and a sandpaper covered popsicle stick to remake the scoop relief.  Here it is in progress:

I want to be sure that the curve of the hood matches the curve in the fascia.  To make sure they match, I made a simple template with foam core posterboard.  It'll get me closer than I can eyeball(and no, I'm not holding it straight in the top pic).