Delamination and thicker layers?

[NVS3D]

Hi all, my first post here. Recently got the Mars and successfully printed both rooks first time.  After about 5 failed custom prints I finally got some that completed!

There were some blemishes however that I would like to fix before I try printing them again.
On one of my models, on a corner, there seems to have been layers of resin peeled away. Is this delamination? If so, how can this be prevented? If I printed the model again without changing anything would I likely get the same result?

   
   

On another model, on the first few layers that were printed above the supports, there seems to be a much thicker layer of resin built up. It's not really something that looks like it can be fixed with sanding etc, so was wondering what this might be and a possible solution?

   
   

Thanks for your time and look forward to seeing if this can be resolved

[cliffyk]

What resin are you using?

What exposure and other settings?

What is the ambient temperature in your workspace?

[NVS3D]

Elegoo grey resin
75s exposure first few layers.
8 bottom layers
8 seconds normal layers.
Room temp is probably around 20c

[cliffyk]

All looks well but he room temperature, 20° C (68° F) is a tad low for optimum results--most resin suppliers recommend ≈ 80° F (26.7°C).

I live in the colonies, Florida to be specific, so that is not a problem for me (my shop is 80° F with the AC on). I have nver printed at 20° C so I don't know if that's a real issue; though I do know somw have implemented heaters within the Mars cover (and/or auxillary enclosures) to raise processing temps.

All that said, I would have a hard time believing that was causing what you have observed.

However keep in mind that the "supports" are in practice "hangers" I.e. the printed model is suspended from the platen via same; they are loaded in tension meaning it not inconceivable that elongation under load of one or more of them could cause the model to move about relative to the FEP/LCD while printing--that could perhaps cause the distortions you are experiencing.

More, or more robust, hangers may be a solution?