Wet sanding direction

[clemsonteg]

So I'm spraying epoxy primer (SPI) on my truck today (in between coats at the moment) and I can tell that I still need lots of practice and that I need to move faster. I have some runs that I will need to sand out. When wet sanding, do I follow the same X pattern method I used when block sanding, or do I go in a single direction? Are there any tricks to removing runs before sanding?

[clemsonteg]

Here's a photo of the job so far

[bs46488]

How does it look now?

I had the same problem when I sprayed epoxy (and being a rookie). after sitting overnight I looked the next morning and could barely tell where the run was because it "flowed" out when it dried.

In my case, I sprayed high build over my epoxy with the runs and all. By the time block sanding (dry not wet) was done, they were not visible.

[kingNothing]

Runs in primer I block as if it were body work, x pattern for me. This may make me sound like a hack but.... If I get a run in primer(bug,fly,) while it is still wet. I take a piece of tape, then lightly pull the run off. Yes this makes a place in the finish. To me it is easier to block out than a run.

[cg285]

why are you wet sanding a run? i would dry sand (X) up until the final sand which would be done wet - and final sand should be sanded in a circle

[randy500]

Sand it in an X and probably do it wet since the epoxy stays soft for a long time. I would try to scratch most of the run off using a new razor blade held perpendicular to the panel, scape it quickly back and forth the scratch the run off, continue scratching on the run until flat. If you don't do that before sanding you will usually be left with a bit of a run that is now just hard to see and feel. Make quick work of the run.
You can do the same with final finish whether single stage or base clear too, prior to sanding and buffing.

[randy500]

I would ditch the plastic on the floor in favor of water. The plastic is dangerous as a trip hazard and collecting then kicking up dust and overspray. Any paint that accumulates on the floor from spraying will wear off or can be removed with thinner.
Water on the floor has its own problems like humidity and water on your hose but I feel those are easier to manage than plastic on the floor.

Looks like the epoxy laid down nice.

[clemsonteg]

Thanks for the advice. The epoxy did lay down quite nice. I've started wetsanding and it's going pretty good so far. I wetsanded the areas with runs with 400 first and I'm wetsanding everything with 600 afterwards. I got some texture/orange peel to take care of, I think I should have used a smaller needle and air cap.

Any tricks to keeping the sandpaper on my block? I'm using a half sheet and wrapped around a 3x5.5 block, but it keeps slipping off.

[hugger6933]

I used to tell everyone to go with the 2.0 needle. Boy was I wrong!! I now use a 1.7 and it cuts down the sanding and the orange peel and it also makes the primer go farther. The runs you had may have been from going too fast. By that I mean not waiting for the flash time to have elapsed. That can and does make runs in any material. Smooth it out and move on to the high build and you are one step closer.

[clemsonteg]

Originally Posted by hugger6933

I used to tell everyone to go with the 2.0 needle. Boy was I wrong!! I now use a 1.7 and it cuts down the sanding and the orange peel and it also makes the primer go farther. The runs you had may have been from going too fast. By that I mean not waiting for the flash time to have elapsed. That can and does make runs in any material. Smooth it out and move on to the high build and you are one step closer.

Runs were totally my fault. Just not enough experience. Didn't move fast enough in some areas or just went blank and made dumb mistakes. I let t flash for an hour or more between coats and most of the runs were from the very first coat.

[randy500]

Originally Posted by clemsonteg

Runs were totally my fault. Just not enough experience. Didn't move fast enough in some areas or just went blank and made dumb mistakes. I let t flash for an hour or more between coats and most of the runs were from the very first coat.

Looks like your doing a fine job from your picture. Hopefully you figure out the spray technique with your undercoats, epoxy sprays a lot like color and clear. The high build primers do not. practice your technique, keep your distance from the panel consistent and your arm movement smooth. letting off the paint trigger at the end of your strokes and getting on the trigger as you start your next pass. You can watch youtube but I feel most of the ones I have seen on there don't use very good technique (mostly excess arm movements and not keeping the gun same distance at all times)
Think of your technique in a way a machine would do it, try to do that. A machine would never tilt, etc at the end of passes, it would stop paint flow while moving and then start again at the right moment.

[projectking]

I spray SPI epoxy with a 1.4....only time I use my 1.7 it's for HB primer or polyester primer.

Your truck looks great, good job!

[clemsonteg]

I used a 1.8, which is probably one of the reasons I ended up with texture that I'm now sanding out.

[72HuggerK20]

Originally Posted by randy500

You can watch youtube but I feel most of the ones I have seen on there don't use very good technique (mostly excess arm movements and not keeping the gun same distance at all times)

The Gunman has some awesome videos on YouTube explaining a lot of different things that make a high-end paint job look good.

[clemsonteg]

It's probably worth mentioning that this was all done using a turbine hvlp system. I don't have the space or the power in my garage for a compressor.

[stevenfromtexas]

hey there brother,
what brand of turbine do you have? i bought the Tptool showtime90 this summer. i just started my priming process too. this is my first paint job and am learning as i go. yours looks very nice!!!