Reinforcing PLA Prints with Resin

[Bucky]

Hello all,

I was wondering if it is a good idea to reinforce PLA prints with resin? I am in the process of printing out ODST armor for cosplay using ST-PLA and I feel reinforcing it somehow may be a good idea. I am not sure which resin to use either as there are many different kinds (fiberglass, polyurethane, epoxy, etc). Any help would be appreciated!

 

[GMer56]

You might want to test your resin of choice on a non-important print first. I've used a one of those plasticy foam paint brushes to apply fiberglass resin to my car and the brush melted. Fiberglass resin has a tendency to melt plastic.
I know that bondo works well but its not as easy to apply.

 

[Bucky]

You might want to test your resin of choice on a non-important print first. I've used a one of those plasticy foam paint brushes to apply fiberglass resin to my car and the brush melted. Fiberglass resin has a tendency to melt plastic.
I know that bondo works well but its not as easy to apply.

Would bondo spot putty be a good idea?

 

[GMer56]

Would bondo spot putty be a good idea?

Yup.

But you can get a gallon of regular ol' bondo for $16 at walmart, which is more bang for your buck. That's a difference of $0.14 per oz of body filler vs $0.88 per oz for spot putty! (assuming spot putty is bought at walmart too) It is usually cheaper to buy in bulk.

But the gallon tin is a 2 part system so mixing it can be tricky, but a general rule of thumb is roughly a 1" line of hardener for every glob the size of your fist. I've used it for cars and a bit of 3d printing and it doesn't tend to melt things. Then if you have a nice, protective coating of bondo you could brush on some resin.

But bondo can substantially add weight to your piece depending on how thick a layer you have, so it might be a good idea to put as thin a coat as possible.

 

[MoeSizzlac]

But bondo can substantially add weight to your piece depending on how thick a layer you have, so it might be a good idea to put as thin a coat as possible.

This! One of the main reasons I went with a 3d print in the first place was to cut out the weight of Bondo that I caked onto my suit to increase durability. The result? Dropped about 30 lbs or weight overall.

 

[GMer56]

This! One of the main reasons I went with a 3d print in the first place was to cut out the weight of Bondo that I caked onto my suit to increase durability. The result? Dropped about 30 lbs or weight overall.

Well, a thin layer of bondo to smooth out print lines/seal the part would be less heavy than the thick layer required for the basic fiberglass piece.

 

[Fallen]

On the resin front, I used Bondo brand fiberglass resin on my PLA forearms to help fill in print lines when I didn't have time to sand forever. XTC-3D is also an option and marketed for smoothing prints.


The image is after one coat of resin on the outside and minimal sanding. Time permitting would have applied a second coat of resin and sanded better.

 

[TurboCharizard]

On the resin front, I used Bondo brand fiberglass resin on my PLA forearms to help fill in print lines when I didn't have time to sand forever. XTC-3D is also an option and marketed for smoothing prints.

View attachment 280685
The image is after one coat of resin on the outside and minimal sanding. Time permitting would have applied a second coat of resin and sanded better.

Second using XTC-3D as an outer coating. Just make sure that you let it set up in a nice warm room and not your basement during the winter

 

[Bucky]

On the resin front, I used Bondo brand fiberglass resin on my PLA forearms to help fill in print lines when I didn't have time to sand forever. XTC-3D is also an option and marketed for smoothing prints.

View attachment 280685
The image is after one coat of resin on the outside and minimal sanding. Time permitting would have applied a second coat of resin and sanded better.

Did you print your ODST helmet as well? If so, how did you orient it and did you slip it in half?

 

[Fallen]

Did you print your ODST helmet as well? If so, how did you orient it and did you slip it in half?

No, my current helmet and visor were a purchase from Sean Bradley.

 

[RedSparrow]

I’ve had some luck lining the interior of 3D prints with XTC 3D from RA Materials. Gave it some structural soundness. I’ve also done it for the outside but I’ve started preferring a heavy glazing spray since it preserves details extremely well and offers an easy to sand but tough surface. Used Bondo for spot filling and it’s held up so far!