Shiny bottom?

Hi folks.

When removing models from the build platform I find the scraper leaves shiny patches. I use the “hold the scraper still and whack it with the palm of your hand” method, so I’m not going at it like an ice pick.

This is obviously going to happen, not much you can do about it. Does the surface need to be roughed up again? If so how and what with?

Thanks.

You can go a LONG way until he surface state of the BP becomes an issue. The only real concern is to make sure there are no chips / sharp bits still attached to the aluminium plate so as not to damage the tank during the initial layers.

I scrape the BP with a metal scrapper before cleaning with a paper towel and IPA, and only worry about the surface state when I start to have adhesion issues which is not often. At that point I use a light emery paper on a flat surface to make the BP homogeneous looking again.

I do not recommend sanding often, as in the long run it will change the thickness of the BP and so the distance between it and the tank. While you can compensate for that with Z-offset, it is especially an issue if you have multiple BPs as they will wear differently.

Note that sanding is not advised by Formlabs directly (although I have never ready anything from them saying it’s a bad idea).

I have one of my build plates in service for 2+ years. Still printing fine and has seen quite a bit of sanding in it’s life.
But indeed, as soon as you have issues with parts not sticking to the build plate, you need to lower the platform(mine is at -0.6). If you print with a lot of build plates, better to not so that much sanding.

The other responses here have been dead on! It takes a lot to get a platform to the point where it’s no longer usable.

Personally I just make sure I’ve removed all the bits of resin, then a quick IPA soaked paper towel to rinse, and then one more paper towel to dry.

If you do this after each use your platform should last basically indefinitely.

Wow, that’s all good to know. I would hate the BP to become a consumable as well.

I’m kind of anally careful with this sort of thing so I’m now hoping for a good few years out of these two, and as a good practice I’ll rotate them often.

Thanks folks.