Any way to neutralize resin/rondo fumes?

[Risu]

I did some filling on the inside of a helmet with resin and then rondo to beef it up and now the inside of the helmet smells like the second most foul thing I've ever experienced. It's been over a week and the smell hasn't faded. On top of that, I'm not really sure if the stuff is possibly still a bit toxic. When the helmet is being worn there will be very limited breathing holes and I'm worried that'll be a big problem. Is there any way to neutralize the smell and (if applicable) the toxic fumes?

 

[EricHart]

First off, it shouldn't smell; once it is fully cured, it should stop off-gassing. Depending on your mix, it's possible that parts of it may cure very slowly (even a few weeks) or not at all.
If it feels dry to the touch though, and you don't feel like starting over, you can try coating the inside with a couple coats of shellac. It dries to a non-toxic surface and is often used to seal off bad-smelling materials. You can also try something like a Kilz primer, which is used for covering over water stains and sealing in odors from mold, pets, smoke and the like, if you don't mind using something thick and heavy, or changing the color of the inside of your helmet.

 

[danbakeronline]

The resin you're talking about is a polyester resin. It's probably one of the most aggressive and toxic of the resin family. It'll eat foam and destroy silicone, and do a number of your bare skin. As Eric said, the curing process doesn't stop once it feels hard to the touch. It's still catalyzing for days or weeks depending on your exact mix. The best thing to do is leave it in a well-ventilated area until the curing process has completely finished.

 

[JBReplicas]

agreed, these things vary from piece to piece, it needs to be given a decent amount of time, in some cases a week to fully settle down. You don't want to run the risk of inhaling these fumes

 

[aron42486]

Not sure if this actually did anything but...

My helmet also had that lingering fume smell for a awhile. I washed the entire piece a week after it cured to clean off the sanding dust and it smelled a lot better.

I dont know if it was the sanding taking off the surface layer or the actual washing, but something got rid of that strong smell.

 

[Volpin]

It'll eat foam and destroy silicone,

Can you elaborate on the "destroy silicone" part? I've got some helmet molds I've been working with - rebound 25 silicone - and I've pulled two polyester resin copies out of it. If this will destroy the mold prematurely in the long term, I'll probably stop. Anything I should look out for?

 

[exoray]

Can you elaborate on the "destroy silicone" part? I've got some helmet molds I've been working with - rebound 25 silicone - and I've pulled two polyester resin copies out of it. If this will destroy the mold prematurely in the long term, I'll probably stop. Anything I should look out for?

The styrene solvent in the polyester dries out the silicones surface, it will get crispy and brittle much sooner than if you use urethane... If you use a mold release it will drastically improve the life of the mold, make sure the mold release you use is polyester resin friendly, as the styrene in the polyester resin will also dissolve most common mold releases, negating most of their effectiveness...

My release of choice is Ultra 4 Polyester Parfilm Paintable Mold Release it works equally well on urethane, or even parting multi-part silicone molds (if you use a platinum cure silicone test to make sure it doesn't inhibit setting) I like this release as it covers all my bases...

Is there any way to neutralize the smell and (if applicable) the toxic fumes?

Give it a bath in warm soapy water, with Dawn dish soap... If it's raw Bondo don't let it soak to long... This will remove any paraffin wax on the surface that was dissolved in the resin, then set it outside to air our for a week or two, if it's above 80° you are golden if not it might take longer, as polyester really starts to screech to a curing halt as you fall into the lower 70°s... Once aired out give the inside a coat of the newer H20 spray primer/paint, or a decent brush on acrylic/latex primer/paint... Let the primer/paint air out for several days...

 

[robn1]

And try epoxy next time, much less stinky than polyester.

 

[Risu]

Thanks for the tips. I haven't washed out the inside yet, but was planning to once the whole thing was primed, there's a lot of primer dust collecting on the inside. I'll try the Kilz primer as well.

 

[exoray]

I haven't washed out the inside yet, but was planning to once the whole thing was primed

You need to wash before you prime, thus the reason I suggested doing it now... Most polyester resin has dissolved wax in it, this wax rises to the surface and creates a thin barrier to inhibit air contact that will make the surface sticky... But it also traps in the smell... If you want to de-smell it getting rid of the wax layer will help, you are going to half to do it before you paint or else you will have paint issues...

 

[Risu]

I meant after I finish priming the outside. As it is now, the rondo isn't sticky, it's completely dry/solid, it just still has a strong smell.

 

[GuntahKela]

Can you elaborate on the "destroy silicone" part? I've got some helmet molds I've been working with - rebound 25 silicone - and I've pulled two polyester resin copies out of it. If this will destroy the mold prematurely in the long term, I'll probably stop. Anything I should look out for?

I had a bad experience that validates this claim. For casting with the Autopart-store polyester resin, it deformed the back of my silicone helmet mold on the first try, leaving fist-sizes dimples and convex forms, although it was locked inside a mothermold. Worst of all, the cast part didn't even cure properly. I ran back to casting with high quality polyurethane resins.

Although I didn't stick long enough to see my molds deteriorate with more use of Polyester, one deformed RTV mold, and all the further deformed castings that I had to repair, was enough to dismiss it.