Sanding scratches on radiata pine
My doors are driving me crazy! I've got 6-panel radiata pine doors, I sanded with 150 then 200, think I got everything smooth, sealed with wood conditioner, stained with gel stain. The first door I put wipe-on oilbased poly, found that I couldn't scuff between coats with 220 w/o leaving scratches I could see at low angle and strong light. So I sanded with 400, put total of 6 coats of wipe-one poly on - that door looks OK a year later, I'm sure part of it is b/c it's hung and I can't see the scratches at the angle of the light. I'm trying to cut down on the number of coats of poly I put on the other doors (that was a bathroom door).
The door I'm trying to do now, I started off the same way (150, 220, condition, stain), after staining I tried a sanding sealer coat of dewaxed shellac - followed by 320 grit hand sanding and I've got a ton of scratches and dull spots. Do I need to get out the random orbital sander? What grit? How to I handle the detail areas?
All the baseboards and casings in the house are (I believe) radiata pine, finest I've had to go with those is 220 grit, 2-3 coats of poly. I don't get why the doors are showing the scratches so much.