Rough sand marks and SPI Turbo

[chevy_power427]

I am currently shaving an engine bay for a friend. I was wondering what could be the roughest grit I can under SPI Turbo and not have issues later on. I will set it in the sun a day so any shrinkage that has to happen, happens. I don't like priming over stuff in this state, but there are so many nooks and crannies, and filler to start glazing and finishing nicely.

 

[Jim C]

I try no not prime over anything more coarse than 180g. You can prob get away with 120 but i would never go more than that.

 

[jlcustomz]

If you want something that can go on thicker & be sanded coaser between a base epoxy coat &2K primer, consider a sprayable poly filler such as evercoat g-2. Can sand 80 grit to start. Need a 2.2 tip to spray it. I find it a real time saver where you want filler build & don't want to hand apply, which requires more sanding everywhere just to remove the roughness you just added. Almost completely non shrinking. Goes on in a dull coarse finish & sands smooth, which works like a guidecoat. Very loud smelling product.

 

[strum456]

I try to avoid poly primer on parts that are "hard to sand". If you need build in these areas, that's another story. With poly, you can quickly end up with a lot of product in an area that is hard to sand it back off, which in my opinion could lead to durability problems later on.

 

[chevy_power427]

I have poly primer, but I want to avoid it, it doesn't sand like 2K, and with all the details, I am going to go nuts, I might as well put some more time and finish everything finer. I was asking the question because I have seen in the tech sheet that 2K turbo can be applied 4:1, which I didn't try yet, and I have it in stock.