I'm new to using Bondo...how long does it take to dry completely? It feels pretty solid and dry in an hour or so but I didn't want to screw it up by sanding too early.
Bondo drying time?
- Thread starter BlindSquirrel
- Start date
Yeah, it all depends on how much catalyst you mix in. Right now, on my Vader resculpt, I've been mixing it fairly hot so I can sand and/or re-apply in about 15 min between coats. You want it pretty solid when you start sanding or it will coat the granules on your sandpaper and "dull" it. Also, you want to use very coarse sandpaper to keep clogging down.
Good luck!
-Sarge
Good luck!
-Sarge
yeah, an hour should be more than enough time. And like feek said it sometimes helps if you start to sand before it is totally set.
I usually use a pea sized glob of hardener for every golf ball sized glob of bondo. A few minutes after i apply it it starts to get hard, still a little plastic-like and a little flexible, at that point i usually use a rasp to help work it into a basic shape. Then once it isn't as gummy i'll knock it down with some 60-80 grit sand paper, then when it is pretty much set i'll go to 120-150 grit, then 220 (or higher depending on the application)........it just takes practice, but it is usually pretty forgiving.
The only thing to watch for is to make sure you mix the hardener in completely...if there are any streaks of unmixed material it will stay sticky forever.
you can also mix bondo with polyester resin to make "bondoresin" (technically bondo is just polyester resin with talc mixed in) bondoresin is a soupier waterier consistancy, I usually use it when i'm in the final stages of refining a form that has to be very smooth and even (after i've done regular bondo work)
bondoresin also makes a good gelcoat/detail layer for fiberglass molds (though it does shrink slightly) and it will set against moist surfaces (like water-based clay) that regular polyester resin won't set against
good luck!
have fun!
I usually use a pea sized glob of hardener for every golf ball sized glob of bondo. A few minutes after i apply it it starts to get hard, still a little plastic-like and a little flexible, at that point i usually use a rasp to help work it into a basic shape. Then once it isn't as gummy i'll knock it down with some 60-80 grit sand paper, then when it is pretty much set i'll go to 120-150 grit, then 220 (or higher depending on the application)........it just takes practice, but it is usually pretty forgiving.
The only thing to watch for is to make sure you mix the hardener in completely...if there are any streaks of unmixed material it will stay sticky forever.
you can also mix bondo with polyester resin to make "bondoresin" (technically bondo is just polyester resin with talc mixed in) bondoresin is a soupier waterier consistancy, I usually use it when i'm in the final stages of refining a form that has to be very smooth and even (after i've done regular bondo work)
bondoresin also makes a good gelcoat/detail layer for fiberglass molds (though it does shrink slightly) and it will set against moist surfaces (like water-based clay) that regular polyester resin won't set against
good luck!
have fun!
Thanks for all the advice! I put down a second coat and had great results by wet sanding. With dry sanding, the paper got gummed up quickly and seemed to "tear" into the otherwise smooth Bondo surface.
Does this sound right?
Does this sound right?
Tetmatek
Well-Known Member
It is not recommended to wet sand bondo due to its porous nature. I f any moisture gets below the surface the result could be devistating if it is not totally dry before top coating or priming.
This is a great product for finishing off bondo work. It does not shrink as much as using the Bondo thinner and is easy to sand with 180 and 320
http://www.u-pol.com/countries/en/downloads/tds/bagdolhv.pdf This is a european company with many great products. They have a spray can primer that has a fantastic film build. Hope this helps
CustomCreations
Sr Member
90% of my modelmaking is done with 'bondo'.Ahem.
If you are doing large amounts I can def recommend a 'surf form' tool- its like a cheese grater in metal, but for wood (dont know what they are called in the US). Once the filler has just 'kicked' to solid-ish, go to it with the surf form. Pratice will get it to the point you can finish things really , really quickly this way.Far,far faster than sanding many times.,You also have the benefit of filler shavings , rather than filler dust!
Bondo shouldnt really clog paper in a gooey-way, so if its tearing your final finish then I would mix a bit more hardener next time.
If you are doing large amounts I can def recommend a 'surf form' tool- its like a cheese grater in metal, but for wood (dont know what they are called in the US). Once the filler has just 'kicked' to solid-ish, go to it with the surf form. Pratice will get it to the point you can finish things really , really quickly this way.Far,far faster than sanding many times.,You also have the benefit of filler shavings , rather than filler dust!
Bondo shouldnt really clog paper in a gooey-way, so if its tearing your final finish then I would mix a bit more hardener next time.
Great_Bizarro
Sr Member
Ambient temperature has an effect on how fast it sets too. Cool weather takes a bit longer.
