Chemically post processing PLA with epoxy resin  

RE: Chemically post processing PLA with epoxy resin

I have a couple colleagues who inject it into rocket fins.  I have not done it myself.  They create passages for it to flow and they inject it.    

RE: Chemically post processing PLA with epoxy resin

Hi @cwbullet,

If I understand correctly, your colleagues print rocket fins in PLA and they smooth them with epoxy resin to allow a laminar flow of air.

Do they place the resin with a brush or de they use other methods of application?

RE: Chemically post processing PLA with epoxy resin

They both smooth the surface and strengthen it with Epoxy.  They use a brush and spatula.  

RE: Chemically post processing PLA with epoxy resin

you can also smooth PLA with acetone and apparently (according to the big G) tetrahydrofuran, which sounds horribly toxic.

RE: Chemically post processing PLA with epoxy resin

I am about to start using casting resin as a clear-coat for 3d printed fishing lures.  It appears to be a common practice for fishing lure finishing - gives a clear gloss coat, waterproofs and hides the layers from the fingers.  If you don't sand the 3d printed part, I don't expect you'll get an amazing result if what you are after is smoothing the gaps between the printed layers with just epoxy - unless you don't use clear epoxy.  If you use opaque epoxy you won't be able to see the layers, and your part will be smooth so there is that.  

Another way to get pretty significant smoothing is with spray lacquer - Rustoleum spray filler primers are a good intermediate step in a sand-spray-sand-clearcoat approach.

There's even a "print" posted in the prints section shows how to mix using spray clear-coat acrylic with spray clear-coat polyurethane that seems to give fast smooth results with no sanding.

RE: Chemically post processing PLA with epoxy resin

I would like to see any photos you generate.  I might try to do it also as a learning opportunity.  

RE: Chemically post processing PLA with epoxy resin

I’ve used xtc3d on my Mandalorian armour I’m currently making. It’s a 2 part epoxy clear coat with a low curing temperature that makes it suitable for use even on pla. It’s somewhat self levelling and even a single coat significantly gets rid of layer lines. I’ve been sanding afterwards anyway before painting. It’s does tend to fill in All details though as well as the layers. 
It’s pretty good stuff but not cheap and it’s a 2 part resin so gloves etc are a must as well as accurate scales to measure the parts out. 

RE: Chemically post processing PLA with epoxy resin

UV resin for SLA printers can be used to smooth the surface, here Thomas Sanladerer tries it out on YouTube.

The advantage with UV curable resin is that it is workable until exposed to UV.

RE: Chemically post processing PLA with epoxy resin

@dan-rogers

I am about to start using casting resin as a clear-coat for 3d printed fishing lures. It appears to be a common practice for fishing lure finishing - gives a clear gloss coat, waterproofs and hides the layers from the fingers.

Yes it works, it is common practice but don't do it.

I printed some rough prototype lures a couple of years ago and they worked well.  So the next step was to pretty them up; very much as you are planning: the fish wouldn't touch them but still kept taking the prototypes.

I think the rough surface made more turbulence and gave a better vibration, whatever it is, the crude version catches more.  'Though I need to rework the design to help them cast better.

Cheerio,

RE: Chemically post processing PLA with epoxy resin

Posted by: @towlerg

you can also smooth PLA with acetone and apparently (according to the big G) tetrahydrofuran, which sounds horribly toxic.

No!

You can't smooth PLA with acetone. I've tried it, it won't work. Best it will do is kinda scuff the surface. 

They say that you can smooth PLA with methylene chloride, but I have not tried it yet. 

I've had great luck smoothing ABS with acetone just by dipping a mop brush in some and gently brushing the surface. 

RE: Chemically post processing PLA with epoxy resin

Epoxy used for different work on surface. In my blog, I published a article about epoxy for aluminum. I hope this article valuable for epoxy users.
Thanks