Official Bondo Thread

S

Soju

Guest
Okay, I bought some Bondo to fill the gaps in a couple pieces. I read the can and it says to mix 1/4 tube (hardener) with 1/4 of the can contents. I've never used this stuff before and I don't want to get the proportions wrong. Would it hurt to just mix the whole can? How fast would it cure? This may be a stupid question, but I don't want to screw it up. Thanks.
 

Pantera

Active Hunter
Don't mix the whole can.It will harden in just a couple of minutes.What you want to do is experiment with it.Try to find a color(bondo is grey and hardener is red.The more hardener you use,the redder the mixture gets ) that dries at the rate you want .If you use too little it won't dry at all.If you use too much it will dry too quickly .It will also create heat .The more hardener you use the hotter it will get.What you want is a light pink color.Just mix a quarter size amount of bondo with a pea sized amount of hardener and mix it THOROUGHLY! See how it dries and adjust from there.Try to mach the color when you mix the batch for your prop.You don't have to be perfect.Bondo is pretty forgiving.When you learn how to use it there is nothing better!
Hope this helps.

TK/BH-1889
 
Last edited by a moderator:

Got Maul

Well-Known Hunter
ay, I AGREE with pantera...do NOT mix the whole can !!!! That would make for a great story though :)

Bondo is not too hard of a science. You find that for a teaspoon of bondo, you could get away with with about a QUARTER of pea's worth to kick it. If you need it to kick (harden) faster, then add double the amount of red juice, but Mix THOROUGHLY until you no longer see red swirlies (or whatever color your hardener is).

Be careful, you want your bondo to harden according to your skill level at laying the good stuff down. I have been doing it for only 2 years under excellent supervision of a propmaster and even now, I still find myself messing up quite a bit ! The trick with this stuff is to layer and layer...don't think you can get it all in one shot...what happens if you think that is you will keep on sculpting and resculpting the stuff, messing it up even more than you had started. So be patient.

Anyhow the point to all of it is you want your hardener to kick at your skill level. If you are just beginning, start off really slow, very small amout of hardener to bondo to allow yourself maximal sculpting time. If you get better, the faster and more kicker you could add. On days where I have no time, I need the stuff to kick in five minutes, but then again, I its not like I am relayering a fett helmet or something, if you catch my drift.

hope that helps.

Another indicator is color of the bondo. When starting, just add enough hardener to SLIGHTLY discolor the bondo towards red (or the color of hardener that you are using) etc.

gm
 
Last edited by a moderator:

Bobbywan

Active Hunter
Great info guys!! I've NEVER used bondo and I will need to very soon so this info is priceless!! :)

Thanks!!!

~Bobby
 
Last edited by a moderator:
S

Soju

Guest
Yes, thanks! I'm SO glad I asked!
 
Last edited by a moderator:

Lynn TXP 0369

Well-Known Hunter
Got Maul wrote:Another indicator is color of the bondo. When starting, just add enough hardener to SLIGHTLY discolor the bondo towards red (or the color of hardener that you are using) etc.

gm
Just a little info on Bondo and hardener... Those pink Bondo spreaders that you get to spread Bondo are pink for a reason....
Your mixed Bondo color should match the color of the spreader and then you know your hardner is perfact for no matter how much you mix up, it works everytime. Food for thought, I think it even says this on the Bondo spreader package as well.

I learned that in auto body class in school 17 years ago.....


***EDIT***

Bondo Spreader package instructions read....

"EASY MIXING.... achieving the correct color proportion of hardener to filler is easy with Bondo's color match spreader. The mixed filler ahould be the same color as the spreader. For complete mixing instructions see the can of filler."
 
Last edited by a moderator:

Got Maul

Well-Known Hunter
IS THAT SO !?! I never realized that, but I guess you're right...

Luckily experience allows me to turn my stuff almost completely the color of the hardener itself...but again, as stated above, only if its a fast and relatively small job...for the jobs with layering and planing, you will want to go nice and slow...so everything is nice and even.
 
Last edited by a moderator:

Blastech

Active Hunter
When filling the dent on a DP, if you used the red bondo stuff, Gap Filler believe, why does it get little pin holes in it? I've did it by doing a layer, it dried, sanded, and repeat, till I had it filled and with a nice curve. But now it's developed a few little holes. What should I do to fix this? I don't know of I wanna paint it yet due to this cause you would be able to tell there used to be a dent.
 
Last edited by a moderator:

secol FETT

Well-Known Hunter
.::edit, not try to bump this just fix the title :):.




ok here you go the formula
if you work with FG you have this products, and you only need to buy the plaster :)

You need:
1kilo of Poliester Resin
4cc of cobalt
2cc of catalyst
800gr of dehidrated plaster

mix all exectp the catalyst, and make a uniform paste, you can reserve 2 or 4 months whitout the catalyst, remember the catalist start to dry all the thing and into lil time you can get a rock :lol:, anyway with all this you can make 1800kg of putty yup, but if you need less just take off parts proportionally :), and i must said this mix if for a 20° to 25° degrees, if you need dry faster add more catalyst and done :)
 
Last edited by a moderator:

bobafett669

Active Hunter
Still being new, I am asking a dumb question I know most of you know. How is bondo used? Looks like it is a 2 part material. I have seen one tube that has a reddish material in it and another that has a clear liquid in it.

Does it mixup like a clay?

Is it safe to touch and apply with your fingers?

I assume it is safe to sand after it drys?

Does it also act as an adhesive or do you need to glue/epoxy first?
 
Last edited by a moderator:

fettcicle

Well-Known Hunter
The reddish tube is for use with Bondo, the clear tube is used for fiberglass resin, so you only want to buy the red. Basically you get a large can of Gray puddy, kinda like a soupy clay. You mix in a very small amount of the red hardener and produce a pinkish puddy. the more hardener you mix, the faster it cures. There is usually a small spatula that's included with the kit which is the approxamate color you want for a decient working time. As far as working with your fingers, it can stick to your skin, but you usually apply it with a plastic spatula anyhow ;) I would wear a dust mask when you sand it, it can come off pretty fast, so you want to sand lightly ..... unless you really load the stuff on :lol: As far as an adhesive, it bonds to the surface of what you're applying it to, but can crack and seperate if the parts aren't connected properly, so you basically want to use Bondo for filling cracks, building up surfaces, and evening them out and not for attaching them..... at least that's my experience with it. You can get a quart can that includes hardener at auto parts stores and larger hardware stores.... but you usually need to buy more hardener, which you can buy seperately ;)
 
Last edited by a moderator:

krillindb

Active Hunter
Just make sure you don't use too much hardener because it will cure way too fast and once cured it will crack and break off. At least that's my esperience with it.
 
Last edited by a moderator:

Rammage

Active Hunter
You definitely do not want to apply it with your fingers. It says it's a skin irritant and that it can be harmful if absorbed through the skin. Definitely use some sort of spatula, or a flexible bondo applicator.

I don't think bondo's strong enough to use as a straight adhesive, especially on high-stress parts like the knee-pads and cod-piece. I'd definitely join two parts together with epoxy first, then use bondo to smooth things out.

If you want to be really safe, you should wear a dust mask while working with the grey liquid. The vapors are supposedly harmful, but I nveer epxericened any pobrlems wtihout one... :wacko
 
Last edited by a moderator:

patiam69

Active Hunter
Not only is it a skin irritant but it gets pretty damn hot while hardening so that is quite irritating as well lol
the stuff "theoreticaly" isnt supposed to fill more than a 1/4 inch or so BUT ive seen people fill in 2- 3 inchs dents with it. i am also sure that after a couple of years of hitting pot holes and speed bumps that bondo fell out along time ago. :p
remember anything that you put bondo on has to be sanded rough, im talking ROUGH, like 50 grit sand paper rough. personally i have always preferred the polyester filler over bondo. it doesnt break, usually doesnt fall out, and is harder than bondo. always wear a dust mask when sanding it though this does no good for the fumes
 
Last edited by a moderator:

cal196

Well-Known Hunter
Bondo is just to smooth over minor inperfections, its not meant to fill in 2-3 inch gapes/holes. Although I have seen bondo mixed with elmers wood glue to fill in quite a large gap, but if I where going to fill in an area that needed heavy filling I would probubly use resin and fiberglass cloth and pull the cloth apart so it is less dense then soak it into the resin and smooth it over the area to be filled, then bondo. A ~good~ car body repairman never uses over a few teaspoons of bondo per dent.
 
Last edited by a moderator:

BigaboyFett

Active Hunter
Bondo smells! I opened my can yesterday and was not prepared and was breathing normally...took in a nice full breath of Bondo fumes and had to close the can immediately since I was so ill from the smell.

If I use 200 grit sandpaper on my helmet dent (I do not have 80 grit), will the bondo stick? Same for Sintra, Do you have to grind stuff up for this bondo to stick?


cal196 wrote:

Bondo is just to smooth over minor inperfections, its not meant to fill in 2-3 inch gapes/holes. Although I have seen bondo mixed with elmers wood glue to fill in quite a large gap, but if I where going to fill in an area that needed heavy filling I would probubly use resin and fiberglass cloth and pull the cloth apart so it is less dense then soak it into the resin and smooth it over the area to be filled, then bondo. A ~good~ car body repairman never uses over a few teaspoons of bondo per dent.
 
Last edited by a moderator:

judz dwedd

Well-Known Hunter
Vinyl and most plastic needs to be very roughed because bondo is polyester resin and talk, and doesn't fully bond to some materials. A fiberglass piece will hold bondo very well, where a vinyl helmet won't without roughing, so the bondo has something to "grab".
 
Last edited by a moderator:
Top