I've done dozens of tanks that way,and probably a half dozen or more were A tanks.I have had very good results.You won't get them absolutely perfect,but one of the A tanks I did like that was done in the late 70's and is still fine.If you are after perfection there is no substitute for the way Brent does them.I strap them to a loader wheel,with the inst.panel side against the wheel.I use Black Beauty sand,and enough gets behind the baffles to scour .With the face against the wheel the sand scours the top(most important)and the bottom.If the tank has a lot of rust I use a gallon of muriatic acid,if there is a lot of varnish I use acetone with the sand.It can take a long time.The tank in my RPU was on the wheel for at least 8 hours.I just go out every hour and check to make sure the straps are tight,and the wheel is still clearing the ground.It also take a lot of washing.It will come clean after a while.I use a finger screen in the tank,not for fine dust,but for chunks.The chunks will score the valve if they fall down in there.I had a real bad tank that I did,and it took around 15 years to accumulate a half inch of sediment in the glass bowl.It was doing it's job.I keep the tank topped off,and the car is driven regularly,gas is cleaner than it ever was,we are not filling them with old cans that sat out in the weather and sun to make water,so it stands a better chance of staying rust free.I do NOT use sealer.I have had a lot of tanks come back that I had done by a national chain.I don't blame them,the chemicals attacking the sealer were not invented then,so how could they guarantee against them?(not alcohol related by the way)All the tanks I had sealed from about 1980 until about 2000 have given trouble,and the ones I scoured with sand and acid have given minimal problems.