How to re-coat a 2 pac board

[Dengue]

Hello, my nephew sprayed black gloss 2 pac on a kwila board, which is a very open grain timber. The end result was a large number of small shallow dimples all over the surface, which I suspect is something to do with the timber.
Can you suggest a way to fill these small dimples? Car bog, for instance?
If recoating a 2 pac finish, how do you prepare the surface ?
Hoping you can help,
Kind regards from one very frustrated wood worker who knows nothing about 2pac

[Fallen Woodwork]

Without seeing an image of the finish, it sounds like it could possibly be fisheye. If there was any silicon or oil over spray from an aerosol or anything airborne that landed on the timber before or just after it was sprayed it will result in small dimples all over the work.

It could be something else but I had the same thing happened 20 years back spraying 2K on kitchen cabinets at a shared workshop/spraybooth when the bloke in the next bay behind a curtain (10m away) sprayed silicon before the paint had hardened. Had to hire the booth for another day the next day, degrease/prepsol, sand down with water + wet&dry sandpaper, do it again.

Some might ask why paint kwila?

[Camelot]

For any good finish the prep is the most important, here's a link to a grain filler application How To Use Grain Fillers - Finishing 101 Series - YouTube (https://www.youtube.com/watch?v=7ClzqlWIDfU&ab_channel=SimpleCove)

With you already applying product you could cut back the surface and apply more product and keep doing this until the product itself becomes the filler, then at least the last finish coat should remain stable.

[Dengue]

Thanks FW, there was no silicone anywhere near the workpiece.

Kwila was the only hardwood timber 25mm DAR that I could find locally in a board 1000 x 120 x 25. Terrible timber to grain fill.

It is being painted a smooth glossy black at the request of my granddaughter for whom I am making an electric guitar stand, as per attached.
I took the workpiece to a professional who specialises in 2k, and he laughed out loud when I told him it was kwila. "Good luck with that"

Camelot : So to recoat and fill the dimples with the black coloured 2k paint, what level of grit do we use on the existing finish for the re-coat to grab? Should we use primer?


507694

[Camelot]

You only need to cut back enough to give a key, so 600 grit should be fine

[Dengue]

Put a primer on, or just more colour coats?

[Fallen Woodwork]

It doesnt have to be silicon per sey, anything with an oil, wax or grease or emulsion that gets airbourne can do it.
However, if the timber hasnt had a prime coat at all that would most likely be a problem.
A pic of the surface would help

[Camelot]

I would just continue and build it up with colour coats, since you have one already on there

[Dengue]

Here are pics after I had sanded the base with 320 grit sandpaper.
I think Camelot's suggestion of additional colour coats is the way to go. Thanks for that advice

[Fallen Woodwork]

Those pics really help
Doesnt look like it was fisheye however those appear to be some significant divets remaining.
The risk of painting topcoats over that is the divets, and what ever caused them may still be evident.
If it was me, I would spray a couple coats of highbuild primer to fill it in, sand and paint again... I could be wrong

[ubeaut]

FWIW many years ago I was spraying a bank counter with nitro and got fisheye in the finish. Prep was fine, no silicone around. No idea how it happened.

Soon found out what could carry on a light breeze. Council depot was behind my workspace and one of the mechanics had been doing some welding over 100 mts away. Turns out the silicone from flux can easily travel over 100mts in a very light breeze and it seems to like making friends with lacquer in its travels.

Who'd'a thunk it?

Oh yeah and fisheye solution didn't work with the flux silicone. Major wash down and full strip back to bare wood, full re sand and prep 8+ hrs later the respray was called off after more fisheye even with drops in the lacquer. Re-strip and prep and coat with Shellac to seal silicon then respray. It was a 12ft x 3ft solid cedar counter-top from from 100 year old national bank. Thank goodness the the counter fronts and sides were all safely inside.

I hate silicon. I have used shellac over silicone affected pieces before this and didn't even think to use it prior to1st re-spray. Worth bearing in mind.

Gotta love the versatility of shellac.

Cheers.

PS Agree with Fallen Woodworkers assessment of pics and repair. Kwila sometimes does things like that especially on end grain but can also do it on long grain often air bubbles sneak out when you're not looking especially on a hot day and with a 2 pack. Definitely looks more like art pockets than fisheye.

I would be inclined to fill the holes with something like Timbermate, sand and then do as Fallen Woodworker suggested.