Bondo Resin Ratio

Joseph Humpston

Hello Stan Winston School! I just bought David Monzingo's lesson on making rod-puppets. One material he used is bondo resin, which he stated in the lesson was bondo body-filler that is just thinned down with polyester resin. Any rate, he didn't really state any ratio in his tutorial. Do you any of you guys know the body-filler to resin ratio I need to use?

Chris Ellerby

We reached out to David Monzingo and here is his feedback:

Hey Joseph,

Bondo Resin can be mixed to a consistency of your choosing, as thick or as thin as you prefer. For me, usually 2 parts Bondo to 1 part polyester resin or thereabouts works well, as it has thinned the Bondo enough to spread but is not too thin that the mixture runs everywhere uncontrollably. If you make the mix too thin, add more bondo; if it's too thick, add more resin. More critical and less easy to gauge is the amount of bond and polyester resin catalyst to add to your mix. I try to always err on the side of not enough, as adding too much can have disastrous results while the usual result of too little catalyst means that you wait longer before you can continue.

Polyester mud is just polyester resin with the thickening agent 'cabosil' mixed into it until the resin gets to about a peanut butter consistency. You can get cabosil from Burman Industries or other makeup effects suppliers, I believe that some fiberglass suppliers probably carry it as well. When you mix the cabosil in the resin, be absolutely sure to do so in a well-ventilated area and wear a dust mask, the particles are hazardous and are very easily inhaled.

Apologies that I didn't cover that in the webcourse, hope it helps you make something really cool.

Best of luck to you,

David

Great questions!

/Chris

Chris Ellerby

Hi Joseph,

I've reached out to the team to see if we can hunt down the answer to this one for you!

/Chris

Joseph Humpston

Thank you Chris! Also, you think you can ask them where you get polyester mud? I mean, do you add some kind of agent to polyester resin to thicken it into mud?

Joseph Humpston

Thanks Chris and David!

Joseph Humpston

Monzingo's lesson showed me some tips that could prove more than valuable to me, such Fiberglass molding, which I could use in making skins for my animatronic creations, as well as Jaw mechanisms.