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Jeff Wisnia
 
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User Example wrote:

blueman wrote:

After many years of playing with ordinary epoxy and Elmers woodfill, I
have graduated to Bondo

Any tips with how best to measure, mix, and handle the material.
The can I bought comes with a measuring cup and talks about using a
1.5" bead per cup.



I like to make a puddle of the bondo and then make a smiley face on it
with the hardener. That's about the right amount.



- Do you mix it all together in the provided cup or do you use
something more disposable?



Go to an autobody supply store. The sell plastic mixing boards. They
are easy to clean up with some lacquer thinner as long as you clean it
up quick. Don't ever use cardboard to mix on since it absorbs some rein.



- How precise do you need to be in measuring out ratios of materials?



Not very. It just controls how fast it gets hard.



- Any tricks for applying and shaping the mixed material? (it seems to
be very
sticky)



You need to sand with rough sand paper (40 or 80 is what I use) before
you apply it so it will stick. Use the plastic spreaders and press down
firmly so it fills in the cracks and crevices and sticks well. Try to
get smooth coats so you don't have to sand a lot. But you can use a
cheese grater to shape it once it firms up. If you find it too sticky
and clogging your sandpaper then you didn't wait long enough for it to
harden.


- Any way to get a longer work time then 3-5 minutes?



You can use less hardener but you still won't get a lot of useable
working time. It's best to use several thin coats anyway.


You can also chill the can down in the fridge and chill an old china
plate to mix it on too. That'll slow down the curing of the unspread stuff.


Thanks for the advice




Some random thoughts from my years of using Bondo to fix everything
except a broken heart and the crack of dawn:


Exposed Bondo doesn't hold up very well to water exposure, so if it's
going to be outside or splashed on frequently make sure to give it a
good covering of paint.

If you are using Bondo to fill "holes" or gaps in wood, the adhesion is
not very good. You can improve that a lot by driving in some screws or
nails part way into the wood so their exposed shanks and heads will get
surrounded by the Bondo.

If you need maximum strength, switch to the Bondo with the fiberglass
filler in it. You can also imcrease strength by burying straight or
shaped "reinforcing rods" made out of coat hanger wire. (Use the heavier
style hangers.)

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."