Comment on Does Prusas textured sheet...work at all?

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j4k3@lemmy.world ⁨1⁩ ⁨day⁩ ago

It can coat the inside of the drier. Use Bounty paper towels as a control when in question. Bounty are often uses in automotive paint shops for a few reasons, but they are trustworthy for composition. If the two plies are separated, they make a good strain filter. That is the primary reason they are used. They also tend to be lower lint though not perfect. A tack cloth is used in the booth with controlled filtered air flow either across or down draft, so it is not a concern for perfect paint.

One of the tricks of automotive painting is to add a couple of drops of Palmolive dish soap to the water bucket used with wet sanding. It makes 3M Imperial Wet/Dry sandpaper last several times longer and acts as a mild degreaser the whole time. Any residue is cleaned in the booth stage using a special Wax and Grease Remover solvent that is the least reactive of the painting solvents. While this solvent is used extensively, still the fact that Palmolive dish soap can be used at all indicates how it is clean, consistent, and chemically irrelevant. Automotive paint reacts with many chemicals but specifically silicon is the worst problem. It causes fisheyes aka little divot like holes to form in the clearcoat. In most situations involving contamination and adhesion, silicon is the main issue that will be very persistent. It is so bad in automotive paint that in the worst cases, we turn to adding an actual silicon solution into the 2k clearcoat and trying to guess what concentration will match the problem area to level it. Otherwise, the entire job must be stripped to the raw surface and start over. Silicon issues only show up in the final wet clearcoat layer shortly after it is sprayed and leveled.

The reason why I have written all of this is to illustrate this point: the silicon is essentially floating on every underlying layer. The solvent has wet the area and the silicon just floats to the top of some filler, 2k primer, sealer, top coat color and when it gets to the clearcoat it blows a hole through it. There are two solutions. Use a two part epoxy primer that is a pain in the ass to sand, or clean the the raw surface with lacquer thinner or virgin acetone. In automotive paint, those two solvents are dangerous for causing a ton of other contamination and reactions issues. However, these are the only solvents that will take off silicon without diluting it and making the problem worse. Alcohol is a joke with no place in the automotive paint world when I was painting. I got out before water based stuff ruined the industry by making refinishing exponentially more expensive. That is only the color coat and some primers, so there may be alcohol used in some way in these, but it will not involve cleaning. Tire shine is the main source of silicon issues in automotive paint.

I have the empirical experience to know what I am looking at with cleaning and solvents. Alcohol is okay for minor issues, but think of it as constantly diluting and wiping the problem across the whole surface. Eventually, just use some virgin acetone to actually clean the thing properly. Paint is just plastic too. Each type requires a different type of tooth to mechanically bond to. With printing, I use 600 grit to lightly knock the shine off of the print plate surface. I go lighter on the textured sheet, but I only use the textured sheet with PETG because it is the only one that takes the textured pattern completely without showing layer lines. I print weekly on average, and use acetone and sandpaper around once a year. When I use glue stick, I clean the plate with dish soap after. I use alcohol in between. You will need an enclosure for ASA, ABS, and any larger PC prints regardless of the sheet or glue. Two IKEA Lack tables with legs stacked using double sided screws, then a clear shower curtain liner, and some tack nails does the job for under $50.

I would never use towels from any drier that has ever had fabric softener used in it for automotive paint. That is a contamination nightmare for me.

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