Best Material for Hiding Seams in Plastic

[Skaught]

I'm joining to pieces of plastic and it will have a noticeable seam if left alone. Is Bondo the usual material people use to hide the seam? Any adivce from the experienced? I've used a little Bondo 17 years ago on my car but not since.

Thanks,

Scott

 

[oblagon]

I'm joining to pieces of plastic and it will have a noticeable seam if left alone. Is Bondo the usual material people use to hide the seam? Any adivce from the experienced? I've used a little Bondo 17 years ago on my car but not since.

Thanks,

Scott

I'd either use Evercoat Polyflex to fill the seam or you could use zap-a-gap to fill it and then sand it smooth.

 

[exoray]

Depends on the plastic type and how big of a seam...

Bondo (autobody filler) works well as a general generic filler, but on thinner plastics that might flex a lot you might experience issues...

 

[Skaught]

I putting four pieces together for a Fett backpack (top, bottom, front and back). The plastic isn't real think, but hopefully it won't be flexing much.

Scott

 

[oblagon]

The Evercoat polyflex is a liquid bondo, so unlike the regular automotive stuff it will flex and not crack. Again I would highly recommend that you use it to fill the seams in your backpack.
You can also use zap-a-gap which is a flexable superglue of sorts. But again it will not crack or crystilize like regular superglue. I would use the zap ot touch up areas like air holes in the bondo.

 

[Lear60man]

On my Jango pack I used some expandable foam to strengthen it from the inside. Cheap and light. Bondo will defiantly work as long as the pack isnt flexing a bunch.
Christian

 

[Nataku]

Whats Evercoat and Zap-a-gap like to sand?

 

[Clutch]

Use magic sculp. Two part putty that you mix together and smooths like glass when you get it wet.

 

[Skaught]

On my Jango pack I used some expandable foam to strengthen it from the inside. Cheap and light. Bondo will defiantly work as long as the pack isnt flexing a bunch.
Christian

I thought about that. As long as there is an opening I assume it won't burst the pack?

Thanks guys!

Scott

 

[Skaught]

Is Evercoat polyflex sold in stores, or mainly online?

Scott

 

[oblagon]

Is Evercoat polyflex sold in stores, or mainly online?

Scott

It sands a lot easier and smooths out faster than regular bondo. You can find it at specialty auto store (not Autozone or Napa) or Amazon sells it as well.

Lear mentioned filling it with a expandable foam; you can pick that up at Home Depot or Lows in the building supplies area. Forget what the name brand is but it comes in a orange can with yellow lettering.

 

[Skaught]

I stopped by Autozone on the way home and they didn't have it, which is why I asked. That's the only auto store I know! Oh well...mailorder time. I've used the foam before...I had a can burst in my shed once. Fun discovery!

Scott

 

[exoray]

I stopped by Autozone on the way home and they didn't have it, which is why I asked. That's the only auto store I know! Oh well...mailorder time. I've used the foam before...I had a can burst in my shed once. Fun discovery!

Scott

One of the only retail places that sells Evercoat products that is easy to find and easy for the guy off the street to purchase from is Sherwin Williams Automotive Finishes... Note they are different from the regular Sherwin Williams Paint stores, you need to make sure it's and Automotive Finish store...

Evercoat products are arguably the number 1 professional grade body filers and sorts, so any real automotive finish supply house will also have them but many won't sell to the public without a business account... Never hurts to call them up though...

 

[Darth Lars]

If this is flexible ABS or HIPS that you want to fill, then the best result will be acquired with real ABS dissolved in acetone or "polystyrene cement" (the liquid kind). Dissolved ABS is easier to work with than dissolved HIPS. Dissolving it in poly cement is better than dissolving in acetone, but more expensive and is best for the final layer.
Apply in layers, and let dry before each new layer. Be careful to store it in an airtight jar because it evaporates quickly. It warps easily if you apply it too thick.

Not be easiest method by far, but the best final result.

I prefer epoxy over polyester resin, polyester resin being the stuff in Bondo. Epoxy has better adhesion and therefore it cracks less easy. Therefore, I suggest epoxy putty over Bondo.

 

[Skaught]

It's just polystyrene. Nothing fancy here.

I found a Sherwin Williams Auto place not too far from my office. I'll have to check it out on a lunch break. Thanks.

Scott

 

[Hirohawa]

Very helpful thread!

 

[swgeek]

Like other people have said Zap-A-Gap is a good filler for small seams.
Lacquer putty is another good filler as long as you get the high quality stuff, not the red bondo crap. You should also prime the styrene before you try any filler (not including Zap or other ca's) Most fillers don't like to stick to raw styrene.