A box I could use some help with! Complete newbie

[wtnhighlander]

1 hour ago, Lucas Purpleheart said:

So it'd be something like: Sand to 80 > Take off dust with tach cloth and compressed air can > Sand to 150 > dust > Sand to 220 > dust > apply 1st coat of satin poly > wait for drying time > Sand 320 > dust > apply 2nd coat of poly > wait > Sand 320 again > apply 3rd coat of poly. Then, apply more coats as necessary?

 

And I was told not to use the shellac on the PH as it will just darken it even though it's clear coat it does yellow the wood a little. I was worried Gloss would love plastic-y so i got satin poly.

Your sanding schedule is fine. What I typically do to remove dust is to vacuum and wipe with a rag moistened with mineral spirits. Tack cloths work fine, too. 

As for the shellac coloring the PH, I can't advise specifically, as I never used purple heart. The spray shellac you pictured is pretty clear but still imparts a slight amber tone. I suppose it could change the PH a bit. But then, so will the polyurathane. My best experience with a 'water clear' finish has been with Deft spray lacquer. That may not be available in your locale. I'm told water-borne polyurathane makes very little color change, also.

Oh, and judging from the pics of the box you made, you might get away with starting at 100 or even 120 grit sandpaper. That box looks pretty smooth.

[drzaius]

80 to 150 grit is a pretty big jump. It'll work, but you'll spend a lot more time with the 150 than if you started with 100 or 120.

[Lucas Purpleheart]

Alright so, I sanded this with an orbital sander. 80 > 150 > 220 as those are all the discs I have. When I got up to 220 I did three coats of shellac with 220 sandings in between. This is what happened, should I have used pore filler? Is this dirt and grime getting in the pores? I am planning on using the satin poly in a day or two to finish over it. 

 

Also, for my PH, someone said to use shellac to allow for better adhesion, but I don't want to darken or give the color an amber tone, despite it saying clear. Should I just sand to 220 and apply three coats of satin poly and be done with it? With the finishing products I have, what would be the best way to finish this?

[wtnhighlander]

Please understand that any oil-based polyurathane finish will impart an amber tone, as well. And although I never use purple heart, it is my understanding that it loses the purple over time, regardless of the finish applied. Some of the others may correct me on that.

You may see less amber tone with water-borne poly, such as Minwax Polycrylic. I believe General Finishes has a similar product.

[Chestnut]

I guess i can't see any dirt and grime in the pores. The pores on oak become very obvious when finish is applied because they absorb it in a different way.

If you are going to do poly over shellac you don't need to do 3 coats but it also isn't hurting anything. Just make sure your sanding it flat.

I made a desk out of purple heart for a friend of mine and for my last coat i used a spar urethane as i read somewhere the uv inhibitors help slow the color change. It's been 3-4 years now and it's still pretty purple. Just a thought.