What filament to use?

One of the upcoming jobs for the MP3DP is to print up some rail clamps that will be used to attach solar panels to our sailboat. I’ve heard PLA isn’t great in situations where heat may be a factor and while we’re not in the desert here we do get warm days. Not 200 degrees mind you. Is PLA okay for outdoor use, exposure to UV, warm summer sun and cold winter days? Or should I be thinking about printing in something else?

From what I have read over the years about PLA only Black (Or really dark) should be used outdoors. Lighter colors will suffer from UV exposure. Over time the PLA will become more brittle as it crystalizes and may eventually break.

I would suggest ABS or NYLON. Both are a little harder to print with. NYLON being the most durable material but also the hardest to print. With your printer I would suggest ABS with an encloser of some sort (even a small tent) to keep the heat in while it prints. That heat will prevent warping and delaminating.

You might have trouble getting the bed to heat up to the suggested 100-110 C for ABS. I have managed to print ABS with a bed at 80 C but that was not using PEI. To help with the bed you can insulate the underside of the bed.

I’ve been toying with the thought of grabbing an Ender 3 just to see how they’re built and how they work - for us Canadians it ends up about the same price as building up another MP3DP (which I’d obviously rather). I could dedicate the Ender to the shop and enclose it for printing ABS/nylon. They list the bed as </= 110 degrees.

I bet the safe move would be to prototype in PLA in any case - since I wouldn’t really know the nuances of ABS or Nylon very well by the time I started running. Sailing season is coming fast though so I better make some decisions…and get into Fusion…

One of the nice things, environmentally, about PLA is that it’s biodegradable. Of course, that then makes it one of the poorer choices for outdoor use. You might look into PETG as well as ABS and Nylon, it’s kind of in between them and PLA IIRC.

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Plastic + saltwater + sun + vibrations (boat pounding on water) sounds like material fatigue just waiting to happen. I know it’s nice to design and print stuff ourselves, but this might be a better project in aluminum. Maybe design the clips and then have a machine shop make them for you?

Or build a MPCNC and route them out yourself (if they wouldn’t need a 4 or 5 axis rotary mill to do).

All in all, it sounds lik an interesting project and I hope you keep us updated!

I could also just buy rail clamps too - they aren’t that expensive. For me it’s a matter of availability. The only stock of such things is quite limited around here so unless I know just the part I need I’m playing a guessing game. I never did think about milling on the MPCNC - trick is the rails are stainless so unless I use a barrier the aluminum will react with the SS. People have done it though. Can’t remember the name of the stuff they say to use. Lanolin is in my head for some reason but that can’t be it.

Here’s sort of what I’m after at the end of the day. arches.JPG Drawing02.jpg

The stuff I want to print would be the double rail clamps that would connect this to the existing rails on the back of the boat and then some clamps that will attach solar panels to the top of the arch. I bet I could darn near use the MPCNC corner assemblies - just need to rotate things so the pipes are parallel. But that takes the fun out of Fusion then doesn’t it? ; )

I have MANY little boat projects to tackle early this spring. Inside and outside. Both machines will be put to very good use.

PETG (same material as soda bottles) prints a lot like PLA, but it’s a big more sensitive because it’s stickier (in my experience). ABS was a pain for me. I don’t like the smell, and I don’t like the 110C bed temps.

If you go with a hotter filament, be sure you clean out the nozzle. If you have some leftover PLA and you heat to 245C, it can turn into clogs. When you go back, the ABS will be a clog at 190C.

I had to finally dig onto this one. Not because of the post Bill - just because I’d been wondering and I happen to have a front yard full of ocean creatures carved out of ice right now trying to help me raise local awareness of plastics in the ocean (which is a thousand kilometres from us).

I was optimistic about the claims and still value PLA for being plant derived but it sounds like the truth of the matter is it isn’t technically biodegradable.


I’m equally confident that the world will find the right material someday soon and we’ll be able to 3d print with it. Until then I’m clear in my conscience in using PLA as it’s not derived from the petrochemical industry.

Ah, so the company selling a biodegradable plastic that’s not PLA says that PLA is ‘degradable’ but not ‘biodegradable’. I’m good with that. :slight_smile: The bottom line is it spends less time in the environment than the other commonly available plastics.

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I missed that little detail Bill! Thanks for pointing that out. Im usually one to be quite careful in checking the source…my bad. More to dig into apparently.