Epoxy Glue Thickening Additive?

HighlanderFX

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Is there something that I can add to my 2 part epoxy glue when combining part A & B so that it becomes more of a filler paste?

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I have a gap between two 3D printed sections of a sword that needs to be filled. Due to the length of the two parts, there is quite a bit of stress at the point of connection when handling the sword. Bondo eventually cracks and separates from the two halves, so no luck there.

Would PolyFiber (polyethylene) work as a thickening agent?
 
What material did you print with? If you used ABS, check out Acryl-green. It's a product similar to bondo spot putty but combines chemically to ABS so it is stronger than bondo, and doesn't crack. I love the stuff.

Apoxie sculpt is another go to for filling in print seams.


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What material did you print with? If you used ABS, check out Acryl-green. It's a product similar to bondo spot putty but combines chemically to ABS so it is stronger than bondo, and doesn't crack. I love the stuff.

Apoxie sculpt is another go to for filling in print seams.


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I'm a sucker for printing with PLA+ unfortunately..

Apoxie sculpt did cross my mind. There's no doubt its strong but I've had cases where it doesn't bond terribly well to my prints in thin areas.
 
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If you go to michael's, you can get a 3D printing pen in the kids section for around $40.00. You can then feed some of your filament through it to cover your seam. If you want to spend a little more, you can get a pen that also has some alternate tips, one of witch is an attachment to smooth things that have been printed.


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I am not familiar with "polyfiber". I have used "microfibres" (may or may not be the same thing) for when I need a filler for epoxy that is extra strong.
I suggest you try it out on something disposable.

Other than that, the go-to thickening agent for epoxy is usually colloidal silica, which is a powder. It not only thickens but prevents running.
Commercial fillers and putties often contain colloidal silica, glass microballoons and talcum powder. Talcum powder is used because it is soft, making it easier to sand once it has cured.

If you do have Apoxie Sculpt, then maybe you could knead some with epoxy adhesive to get something with hybrid properties. I find it likely to contain talcum powder though, so it wouldn't be as strong as epoxy thickened with other things.

BTW, would it be possible to modify your 3D file to make the two parts interlock? Then you would not need much adhesive.
 
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If you want to use epoxy as a filler you can add particulates too it. For instance, sawdust or sand. I've done it and it works alright. A lot of woodworkers mix sawdust will Elmers wood glue to make wood putty, the principle is the same. You can sand a piece of plastic, collect the dust and mix it into the epoxy. It doesn't have to be plastic, you can also use metal powder like aluminum.
 
There are the proper fillers for epoxy and polyurethane and probably even works with polyester. I have also used this stuff in silicone. When I bought my jar, I thought it was expensive for the amount the amount I got. Having used it many times now, this stuff goes a really long way and you can mix it in and know the resin will cure.
 
With polyester resin I've used talcum powder to make a putty/filler.
As I posted above, talcum powder is often used in commercial fillers such as Bondo.
It also makes the putty sandable. Home-made epoxy putty with only colloidal silica and microfibres can be a b***h to sand.

Stay with epoxy for when you want to join two parts together. Polyester is not as good as an adhesive and in my experience (with those brands I have tried), it is not as tough as epoxy either.
 
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Stay with epoxy for when you want to join two parts together. Polyester is not as good as an adhesive and in my experience (with those brands I have tried), it is not as tough as epoxy either.

Yeah, this is what I have found as well. I added the filler to the epoxy and it has worked wonderfully. Thank you everyone for all the great advice!
 
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