Finishing dilemma

[volcaster]

I'm having an issue with a Martin mahogany neck. This isn't my first rodeo, but I haven't exactly ridden the bull for a full 8 seconds. Although I have had great outcomes finishing acoustic material of mahogany, for some reason I didn't get then grain filled properly. I have followed the Stew-Mac Martin nitro recipe before with excellent results, but something went awry this time.
Dan Erliwine prescribes that if you stain the bare wood with water base stain you should:
1. Wipe on stain
2. Shoot sanding sealer ( I used solvent based Behlins )
3. Fill grain - I used Behlins water based mahogany filler, it has a reddish color.
4. Shoot another two coats of sanding sealer. Scuff sand lightly
Wipe away excess filler, and then begin shooting the clear nitro.

The outcome was, around the neck joint and parallel to the nut where there is a lot of grain, the filler filled in nicely, but I repeated the filling steps because last time I used this recipe, the grain didn't fill properly, but the rest of the neck and headstock did. Now it's just the opposite. The grainy areas filled nice
and smooth, but the neck and headstock did not. One other thing, the areas that filled smooth, the color of the filler can be seen in the pores, I stained over the filler as well. Is this correct? Should the Behlins be colored?

Long story short, what are my options? Do I have to start from scratch, and if so, what would be the correct recipe.
Or
Can I sand down the clear coats, and fill the grain again, and then shoot the clear again?

Here are some photos




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[mirwa]

To fix, spray more clear, put lighter coats on. Then flat sand.

As to what went wrong

Without having done the job, I am making assumptions.

My first assumption is that the surface after sealing was not fully levelled smooth, before putting the nitro on.

My second assumption is the coats of nitro were layed on to thick and softened the earlier coats, so you get sink back

Steve

[volcaster]

Ok, thanks for your help. So if the clear coats are too heavy, the grain pores don't level? I'm not sure what you're telling me, because I don't want to do that in the future. Can you explain what happens.

I'm pretty sure I applied the sealer coats before shooting the clear, but they were just scuffed sanded.
Should I scuff sand the clear coats that are on there now, and then start with light coats? How many light coats?


Thanks so much for your help!

[mirwa]

Any paint / lacquer that drys from exposure to air, can soften when more coats are applied

So when you use a sealer that is air dried / sand it and then follow up with a heavy coat of lacquer, this lacquer can soften the sealer, so the sealer sinks further into the grain, the more heavy the coat of lacquer the more prevelant this issue becomes.

A way around this is to apply light coats of lacquer, enough to wet the surface but not too great to soften the earlier coats, how do you know how thick, unfortunatley that is where experience comes in, literally impossible to explain via a forum but seconds to show in the real world (not digital world).

I believe you need about 3 more light coats and then wet sand and continue from there

Steve

[volcaster]

Thanks brother !