I don't know if this matters

[natas2000]

I have few wood tools and talent with wood, and I'm in a very small space.
But I got a 4' 1x10 board cut up to mount a 1x30 sander on it. I got it cut in 12" lengths.
I mounted the machine then put a back on it and another board on the left side if your looking at it. I mounted the controller on the left side for the DC motor.
2 questions:
#1 the bottom board has a 2" wave from either the factory cut or when Lowes cut it. The seam has a gap about the thickness of a play card. I used #8 screws 1 1/2" and its tight. I have not used any wood glue on it. If its that thin can I use wood glue or CA glue? Or do nothing? I don't have a planer.
#2 I did use wood dough on the boards, because the wood dents easy and I had a small container. It seemed to work well.
But I guess I need to paint it now.
Any type of paint should I use? I don't have a very good area to spray but could roll it on. Like some kind of flat Black?

 

[RTM]

1 the bottom board has a 2" wave from either the factory cut or when Lowes cut it. The seam has a gap about the thickness of a play card. I used #8 screws 1 1/2" and its tight. I have not used any wood glue on it. If its that thin can I use wood glue or CA glue? Or do nothing? I don't have a planer.

Wood glue is not a gap filler, nor is CA glue. They won’t add any strength, and may take dozens of applications to close a gap. Epoxy is your gap filler.

Pix may help

 

[Renegade1LI]

This is for mounting your sander, maybe try some spray on bed liner, durable and will hide imperfections.

 

[whateg01]

To mount a small belt sander to, I'm not sure I would worry too much about what I'm imagining you are describing. But your description is a little tough to follow. Are the 12" pieces each a side to a box that the sander is bolted to the top of? Are you saying the cut is not straight? I'm not sure what you mean by a wave. A planer makes a board the same thickness, so if the end isn't straight, it won't fix it. But Lowe's didn't make the board 3/4" thick, either. Tldr; pics!

 

[natas2000]

The hole is on the bottom board.

 

[whateg01]

So, is the cut not straight? It's the cut end butted up to the face of the board on the left? Do you own a sander? So much missing info

 

[natas2000]

No I will try to get a better picture, my internet has been mostly off the last three days till tonight it was fixed.
Yes the cut was not straight in the middle of the board.
I used #8 1 1/2 screws and it tightened up the gap.
I don't need to fix it but was just trying to make it better and try different things.
I have the 1x30 sander but I do not have a palm sander right now.

 

[MongoTA]

The hole is on the bottom board.

Going out on a limb here, but are you referring to this, below in red? If so, I'd refer to that as a "gap" between two boards.

If that gap is what you're referring to, honestly, don't worry about it. Wood moves, and when joining a couple of 2x10s together with screws, a perfectly tight joint today might open up a bit tomorrow. It's not a huge gap, you could use epoxy or you could even mix some fine sawdust in with Titebond glue if it really concerns you. Unscrew the boards, apply the sawdust/glue, then screw together. Wipe off any excess with a damp cloth.

If the round hole is what you want to fill, use a wood filler and a putty knife. Wood filler typically shrinks as it dries, so fill, let it dry, then fill slightly proud. When dry, sand. An alternative to fill the hole would be to drill through the hole with (for example) a 1/4" drill, then glue a 1/4" wood dowel in the hole. Hammer the dowel in, then cut it flush with the wood surface with a hand saw, without scratching the wood with the teeth on the sawblade. Then sand it flush.

 

[whateg01]

An alternative to fill the hole would be to drill through the hole with (for example) a 1/4" drill, then glue a 1/4" wood dowel in the hole. Hammer the dowel in, then cut it flush with the wood surface with a hand saw, without scratching the wood with the teeth on the sawblade. Then sand it flush.

If you really want to go overboard, which any of this beyond screwing it together which you've already done, get a plug cutter and cut plugs with matching grain so you can't even tell there's a plug there! I think that's a mounting hole though. You said bottom board so maybe that's how you are bolting it to the bench? In that case just fill it with the bolt.

 

[Renegade1LI]

You're expecting a cut made by lowes to be square & true? If you're painting it just caulk the joint first.