question about bondo

yeah as much as we hate it unless you own a rat rod and just don't care about the looks of your car , we have all used bondo , so today working on a door on a 46 chevy and at the bottom had a few pin holes so I welded them them skimmed bondo , let it dry a few hours skimmed it again and it made a area about a foot big on my door So hot I could not touch it , now this is not old bondo and I've been using out of it for 2 projects now and yes I'm using the same hardner the first skim did not get that hot but the second coat was smoking Hot ((( you could not touch it ))) anyways I know the chemical reaction between the bondo and hardner and it does get warm , any idea as to what caused this ? should I sand it off and do it again ? Oh by the way it was that hot for aprox 45 minutes , but now that its cool if feels hard

 

it sounds as if you mixed it "hot". not trying to be funny but that is the term for too much hardener. a friend of mine once mixed kitty hair so hot that it warped the panel he was working on. it should be fine but may be brittle.

 

too much hardener, sand it all off and start over

 

i agree with blt2go, what mixing ratio did you use for both mixes

 

yes you uesd to much hardener and you need to sand it off because if you dont you can risk it bleeding through the topcoat later leaving a spot underneath

 

Did you scuff the first skim after it had cooled and hardened?

I ask because, i remember that when I have used it in the past the outermost layer seemed to not want to cure all the way. It would sometimes gum up the paper, maybe the hardener bleeds out a bit?

I'm not sure...otherwise, yeah, just mixed too hot.

 

And don't use Bondo. There are a number of FAR better products out there. I use Evercoat Rage.

 

aint nothing better then Bondo , Lol , anyways no it wasn't mixed hot I mixed it the same way I have always did , I think it maybe a strange reaction with the metal , I did however sand it back off it sanded normal , but upon putting on the first skim again it acted fairly normal just a bit warm but let it sit 30 minutes then sanded mixed a new batch and skimed again and it's hot again , I tryed to skim a cardboard box sanded it and skimmed it again and it did not get hot , must be a reaction with the metal

 

It's not a reaction with the metal. You are mixing it too hot. It's a chemical reaction between the two parts.

 

try it on some paper and see if it catches on fire

 

I agree ...I like evercoat alot better!!

 

Exactly!!! It is absolutely NOT a reaction with the metal you are adding too much hardener. If you are just eyeballing the amount of hardener you are adding (which almost everyone does) even a small difference from one batch to anoher can make a huge difference in the chemical reaction and the heat generated by that reaction. The best way to judge the amount of hardener being added is to run a ribbon across your puddle of filler. If you make a puddle 4" across you should run 1 ribbon of hardener from one edge to the other. Obviously the amount of hardener would have to be adjusted up or down from there if you are mixing larger or smaller puddles of filler.

 

did you knead the tube of hardener before you used it?

 

too much hardener,coupled with the heat from the first application,caused your second batch to really heat up, simple really



skull

 

Try a can of Evercoat Rage and you might just take that back. It is a night v.s. day difference, in every single aspect.

There are even some out there who say that there is even better stuff than that, too!

If you were withing driving distance, I would drop off a can. Seriously, drop $14 on a quart. You won't regret it.

 

I would also let the first coat of filler harden and cure for more than just a few hours. Leave it alone for a day or two. That will ensure that the first application is finished "gassing out" and shrinking. Then sand with an aggressive grit to leave a rough surface for the second coat to "grab".

 

I don't know, I have a car here with bondo in it and I'm still not sure they cared what it looks like.

 

Believe it or not .I think its normal.One time I held bondo in my hand and Whiled it cured it gets hot .To hot to hold in your hand .

 

there is a tube of body filler that is like 35-40 bucks per tube... its pretty much the best on the market, is more closely related to fiberglass resin, goes on like glass, and doesnt absorb water. I would use that if I were you. I agree that it is hideously expensive, but like I said it will last longer and not absorb water. Look into it.

to answer your question, sand it off and redo it. The color of bondo should be a light salmon color when you mix the hardener in. just fyi. a dime sized amount of hardener should be used on roughly a glob about 2.5-3 inch circle of bondo less than a quarter thick (that should get you started).

 

I put on my fair share of filler and the more hardener you add the hotter it will cure.your second coat will away be hotter then the first. the metal will dissipate the heat in the first coat while the second coat the heat is driven to the top because of the first coat. Adding too much hardener will give you a lot of pin holes.So if you find you are having a lot of pin hole you know you used too much hardener. Rule of thumb with filler is one inch of hardener for ever golf ball size of filler.

 

well anyways got up this morning and sanded it down and all is good, But I think I may look into this evercoat stuff been hearing about it for awhile now , but I live in such a small town that all we have is a mom and pops napa and they don't stock it so next time I'm in a bigger town I'll pick some up, Does it mix the smae as bondo ? does it sand easy ? what makes it better ?

 

dotto,ditto

 

Did it smell good? sand it off, and do it again, I also look at the colour of the mixture with the correct amount of hardener the putty will always be about the same.

 

Best answer I have seen yet

 

i know of a bodyman that was a real hack
and he loved bondo he said you can fix
ewerything with it and one day he had a hole
in a toth and fixed it with bondo thats when
he realised it get hot while curing hahaha

 

Just a suggestion, but anytime I'm repairing anything down low, especially doors, I always apply a thin coat of duraglass first to seal and waterproof any pin holes I may have missed before applying body filler.

 

If it were me I would remove the door cut out the area and weld in a new patch panel, grind the welds and you wont have to worry about bondo cracking or falling off the door when you slam it for some reason. my opinion only.

 

That is the funnies thing I have heard all day!

 

use drywall compound !! it sands alot eisier and doesnt look like hell after a few years. you just have to stay out of the rain and cant wash your car no more. it shud be on the shelf at used car places rite next to that stop leak shit ant transmedic stuff

 

Bondo is the new baremetal look

or What if a Mime bought out Boyd's?




I might not be all THAT good myself but...
that's just wrong man... wrong wrong wrong