Bondo vs Latex Putty?

Bondo is essentially a "rubber" putty, cures faster and hardens better than a latex putty. Resists water and takes well to paints.

I've seen Bondo used on a couple of doors.

bondo is talc added to putty, and isn't resistent to water unless it's covered with something. it will be harder than a latex putty.

I'm not sure the definition of "putty" as used here, but the Bondo I am familar with is a 2-part epoxy product. I never getting long enough setting time but I've used it to repair dry rot after digging out the infected area and treating with a borax solution.

I know Bondo resist staining. The wood sucks up the stain first. Paint is the best cover up.

Nonsense. Bondo is a two-part polyester resin, with various fillers of which talc is only one of several. Polyester resin isn't the same thing as putty. Bondo includes a hardener. Putty doesn't.

Can it be primed with something like Kilz, or does it need something special?

Latex putty will last 5 years, its junk. Bondo the 2 part epoxy will out last you and maybe the wood.

I disagree....Bondo is a polyester resin NOT an epoxy.

Epoxy is a better material & more expensive than Bondo.

For interior repairs, Bondo is fine, for exterior Bondo is "ok" except for redwood.

If you want an exterior repait to last use an epxoy ........like WoodEpox or LiquidWood from www. abatron.com

cheers Bob

Well, one reason I like Bondo is the speed at which it sets up. That can be an issue for some. It files, sands and paints well.

Bondo cures and becomes solid whereas putty will remain soft. Bondo putty refers to the putty like mix before it cures. I'd use it for rotted areas which are cleaned to good wood. I've used epoxy but it is more expensive than the polyester, Bondo. To extend epoxy in wood, I sometimes blend with saw dust.

Yes! No.

Cover the Bondo with paint - Not Stains!

Frank wrote in news:h211dh$ue2$ snipped-for-privacy@news.eternal-september.org:

While it's still plastic,it's easier to shave down,cuts down on dusty sanding.

try RAKA epoxy(a thin,boat-building epoxy); they have kits that are not as expensive as West or System Three,and they aren't the polyester resins either.

There are all sorts of fillers you can use with thin epoxy; Wood flour,plastic microballoons,plastic fibers,chopped glass fibers,and fumed silica.I mostly use wood flour and fumed silica.

I've used Bondo several times before, for exactly the purpose you're proposing, and it's worked well. I always used an oil-based primer on it. No idea if a latex primer would work or not, but it sure oughta be primed with something.

Bondo is talc (and other minerals) added to *polyester resin*, not putty. It cures when a catalyst is added. When cured it is reasonably hard but not as hard as plain polyester resin or polyester resin with cab-o-sil. Talc in rock form is about as impervious as you can get, shouldn't be much different in powder form; polyester resin isn't affected by water.

I thought bondo was a type of epoxy since its two part, wont bondo painted last a super long-long time

Just because there is a hardener...doesn't necessarily make it an epoxy. (although, I am not a chemist)

". . .(although, I am not a chemst). . ."

I am. Bondo is an unsaturated polyester resin which "sets" through the action of a peroxide hardener.

Misc stuff: -Reduce the peroxide level to slow the cure down and give more working time. Test your ratio, too little peroxide may not produce a complete cure.

-Good epoxy beats good polyester when exposed to weather. However, in this application, the wood will go first. You must measure the two parts correctly. Proportioning errors can produce degraded epoxy.

-Good epoxy costs more and can cause allergic reactions.

-I used painted Bondo ifor a rotted wood repair at my daughter's house in Tampa. Looks good after 4 years.

-Jason

I have some French doors where a dog scratched pretty deep into the wood that surrounds the glass panels.

Would your recommendations work for that if I build it up in layers?

Andy

You don't need layers with either polyester or epoxy "putties". Best to overfill slightly and cut off most of excess with a chisel after it has set but still not really hard. Sand smooth when fully cured. OR - just over fill and sand flush.

The nice thing about Bondo (polyester putty) is that you can control the set time to a degree. Even setting slowly it is *much* faster (minutes) than epoxies (overnight); additionally, it doesn't blush amines like epoxy nor does it degrade under UV like epoxy.

With either, you need to *thoroughly* mix the resin with the catalyst. With Bondo, the colored "cream" hardners are easier to use than liquid as the color tells you visually how well they are mixed.