Dan Gilchrist said:
… who told me none of their resins are suitable for outside use…
that astonishes me.
if i think about glasfiber watertanks, pools, boats and vehicle carrosseries, that are all made of resin (and glasfiber) and hold up for decades - resin must have some resistance.
Korm Kormsen said:
Dan Gilchrist said:
… who told me none of their resins are suitable for outside use…
that astonishes me.
if i think about glasfiber watertanks, pools, boats and vehicle carrosseries, that are all made of resin (and glasfiber) and hold up for decades - resin must have some resistance.
Korm, All resins are not the same. The ones you speak of are generally epoxy type cured by chemical reaction. The SLA printers use photopolymer resins cured by a UV light.
Maybe the formlabs people are being somewhat conservative.
I read several articles on this subject, by people who had nothing to gain or lose (i.e. a manufacturer). Actual people that exposed their stuff to daylight.
There’s very few unpainted plastics that weather well outdoors, period. Most are black, with lampblack to block the UV and restrict the oxidation and decomposition to a very thin outer layer.
I’m fully confident that painting this stuff would protect it well, I’d be more worried about the paint itself.
Greg
Greg Elmassian said:
Maybe the formlabs people are being somewhat conservative.
Seems there view is that is not the intended use. Check out https://forum.formlabs.com/t/long-term-material-degradation/11017
I read several articles on this subject, by people who had nothing to gain or lose (i.e. a manufacturer). Actual people that exposed their stuff to daylight.
Please provide links! I have found very little info regarding this subject and I am most interested. I’ve finally decided to ask my own questions https://forum.formlabs.com/t/printing-finished-parts-for-outdoor-use/22448
There’s very few unpainted plastics that weather well outdoors, period. Most are black, with lampblack to block the UV and restrict the oxidation and decomposition to a very thin outer layer.
I’m fully confident that painting this stuff would protect it well, I’d be more worried about the paint itself.
Greg
Agreed, I have done my own tests of painted and unpainted PLA, ABS amd PETG printed parts exposed to our New England conditions including direct sunlight with temps over 100 to below 0 and encased in ice! Bottom line - A coat (or 2) of paint makes a difference.
As I’ve said, I’m interested in SLA printers, but hard to justify if the parts won’t last. Currently, If one of my ABS coupler mounts fails, I can print another for $.18.
-Dan
Dan, I read that link, and I did not come to the same conclusion, here is a post on that very link you provided from a formlabs employee:
Long-term exposure in a UV chamber might degrade the part. UV exposure degrades all organic materials, but our resins are more resistant than many common plastics like ABS. UV exposure in a cure chamber will be significantly greater than that of a natural environment and we’ve tested parts outside for over a year outside and haven’t seen any obvious wear.
Reading the entire thread, some people maintained that the SLA resin continues to cure forever, some people say that it cures and is finished. The more technical papers I read said the curing stops at a point, remember not all people on that thread were materials engineers.
A good point from Frew above is that outside is quite different from an intense UV curing chamber.
I’ll look for more, but there’s also a statement in that thread that the SLA resin is more resistant to UV than ABS for example.
So, I come back with my original feeling, that SLA resin is more resistant to UV, but you can paint it anyway. I noticed your examples are for a filament printer which was not the subject. Also not intended was filament vs. SLA.
Greg
Greg Elmassian said:
Dan, I read that link, and I did not come to the same conclusion, here is a post on that very link you provided from a formlabs employee:
Long-term exposure in a UV chamber might degrade the part. UV exposure degrades all organic materials, but our resins are more resistant than many common plastics like ABS. UV exposure in a cure chamber will be significantly greater than that of a natural environment and we’ve tested parts outside for over a year outside and haven’t seen any obvious wear.
Yeah I’ve seen that supposed test mentioned a few times in different threads but none actually show these parts or provide any details of the test. Oh yeah, we tested, it’s fine, trust us.
Reading the entire thread, some people maintained that the SLA resin continues to cure forever, some people say that it cures and is finished. The more technical papers I read said the curing stops at a point, remember not all people on that thread were materials engineers.
A good point from Frew above is that outside is quite different from an intense UV curing chamber.
I’ll look for more, but there’s also a statement in that thread that the SLA resin is more resistant to UV than ABS for example.
I realize the OP was about painting the parts but my interest includes the overall use of SLA resins in outdoor garden railroading. Maybe I should start a separate thread.
So, I come back with my original feeling, that SLA resin is more resistant to UV, but you can paint it anyway. I noticed your examples are for a filament printer which was not the subject. Also not intended was filament vs. SLA.
Greg
Um, you brought it up. I spoke about my plastics to support your statement “There’s very few unpainted plastics that weather well outdoors, period.”
What I usually do with good results is to paint 1 coat, wait til dry which doesn’t take long about 5-10 minutes spray again repeat at different angles. Don’t go too heavy. 4-5 coats is great. If I’m doing more colours I wait several hours or better until the next day before masking and painting the next colour. I wait several hours or until the next day to give the piece a shot of clear matte.
If you rush the job you might get wrinkles or other reactions.
If you are painting couplers you could also try using acrylic paint that comes in small craft sizes in all kinds of colours and it is cheap too.
I use Krylon, ValSpar, Rust-Oleum, and Scalecoat 2 sprays. Typically, I’ll paint on a day when I know I’ll have time to go from primer to finish coat without interruption. Primer, repeating coats every 15 - 20 minutes until fully covered, wait about 40 minutes, then top coat, again with coats every 15 - 20 minutes until completely covered. If I need to do multiple colors, then I wait a day or two to mask and paint.
Later,
K
On SLA printings?