:DO NOT USE Bondo in this application!
:been there, done that..............Bondo is not compatible w/ redwood.
Oh, geez, too late! Yesterday it was threatening rain and I got the idea
I better get something in there or the cracks would be filled with
water, which would prevent anything from working. So, I quickly grabbed
my Bondo-like fibre glass polyester product (Evercoat Home Fix Super
Strength Universal REpair Filler) and mixed up about 2 tablespoons with
hardener and slathered it into the cracks. It rained a lot last night. I
sort of doubt that the stuff has set up very hard yet, and I could take
a putty knife and scrape most of it out, but obviously can't get the
cracks clean. I have some P.C. Woody 2-part wood epoxy paste I could
:I repaired a number of south facing redwood window sills (~ six sills)
:(southern California, ~15 to 20 inches of rain, no freezing) with Bondo
:& then painted w/ a high quality primer & oil base paint.
:The results lookes fantastic!!!!.......for about a year or two.
:Now 15 years later, sills are just as messed up as be I restored them
:I did remaing sills (~12) a few months later, same process except I
:used Abatron Wood Epox instead of Bondo, the sills are still in great
:shape, need some minor sanding & repainting
:Both companies make quality products, I used both.
:Their stuff is not cheap but if you value your time, use it.
:Both sell mail order, Smith may have a local desrtibutor in your area &
:you might save some on shipping.