1) Please confirm...oil based finish over laquer sealer is ok. Laquer finish over oil based sealer is not ok.
2) How much time does Boysen laquer sanding sealer need to dry?
3) I will be using Boysen sanding sealer. Do I use this as is or does it need to be thinned?
1. Yes
2. 4 hours should suffice on a warm day, but best results overnight.
3. Either way works. I prefer straight from the can and apply very thin coats.
Blotching I avoid by applying a thin coat of sealer on a suspected piece, then sand it with 220 grit sandpaper till everything is smooth and even. Then I apply stain. (I am aware that you should stain first, but...)
Stain applied and wiped the excess off after 10 mins. this will allow it to dry faster and give you an even shade without blotches.
Next step would be to apply topcoat. Several layers until you achieve what you seek.
If you can get hold of a wood conditioner locally it will help you stain better, that is if you can find one.
If you use the one step process I told you, after the sealer and sanding, you can apply the finish with light coats. If you need it darker, apply another after a day. Do not apply thick coats to get the shade you need.
Like I told JojoD, I strongly suggest the Ace finishes especially the stain. You can also try the ones from sandolin which is even better.
Brush on finish will require you to thin the finishes about 5% only to keep the fluid flowing and reduce bubbles. Brush slowly and lightly avoid starting fron the corners to reduce drips.
The first topcoat after the stain should be done with very light hands and care as the topcoat chemicals can reactivate the stain and mess it. After the first coat, suceeding ones should be a breeze.
Sand between coats except after stain. You can use 180 or 220 grit. On the final coat, i sand from 220 to 3000 grit depending on the sheen I seek. But you can stop anywhere that suits your needs.
Applying wax such as car wax makes the polish look good.
Hope this helps.