Lacquer can re-catalyze itself if you want to put another coat on or try the thinner and may look nice for a bit but lacquer just isnt durable enough for pinball, Your best bet is to sand it off and use another product. Automotive clearcoats are the way to go.....Good luck!

those are to some degree belt sanding marks. that's why it's on the inserts too. after the playfield is cut, the inserts are glued in place, then the whole PF is belt sanded on a large sander to level the inserts to the wood. they don't do much finish sanding after that, just screen and clearcoat. after the lacquer shrinks (which it always does with time), the sanding marks show up. Add to that the PF is sanded in the direction of the wood grain, and often you have that happening too due to expansion/contraction of the wood due to seasons and humidity.

Even 2 part urethane PFs have this effect to some degree. Because the clearcoat is thicker/harder than lacquer, it's less of an issue.

Short of sanding with 600, touching up, and clearcoating with 2 part urethane, you can't really fix this. The lacquer clear doesn't have enough film thickness to allow it sanding out the marks. With 2 part urethane, there's a lot more film thickness, and these sanding marks can be polished out quite easily.

does your BOP have diamond coat?
you can usually give it a nice coat of wax to keep the dirt out.

Very risky using any thinner especially with a brush. "reamalgamating" does that mean melting??

if you use furniture lacquer there is a good chance it will yellow over time and will look extra crappy.

I first saw this single pac clear on this web site being used on a pinball playfield being rolled on.

http://www.aussiearcade.com.au/showthread.php/41828-Theatre-of-Magic (need to sign in)

I think this product works well because it is flexible and hard but not hard enough to crack like other clears when the ball hammers it. You don't need spray equipment to use it but it does spray nicely anyway. I have used it and very happy with the results

https://www.kbs-coatings.com/diamondfinish-clearcoat.html

Don't be so definite. Diamondplate was first applied to roughly ten Banzai Runs ("XR10") back in the day, and to an increasing number of test machines for every machine between that and T2.

(I own original DP BoP, DP FH, and have a DP RG playfield.)

Yeah, I have a diamondplate Rollergames as well.

*edit* THAT IS A DIRTY <BLEEP> <BLEEP> PIECE OF <BLEEP> TO GET RUNNING.

just FYI

you will achieve essentially the same effect by shooting it with another coat of lacquer as that will reactivate thunder coat. if it was me I would do this and use a spray. if your right andthefinish is really cracked its going to look like a total and complete nightmare after the first coat. it will nearly appear to be bubbleduo and a total loss. respray it and then sand it and repeat... It will rapidly come down and level. after the first coat adjust thickness to required, not so much to lay down a heavy coat to level it, lacquer does not do that very well... More because you want to nearly liquefy the entire coat top to bottom which will help in leveling and you need more solvent, if you have a gun spray a thinned product.... But I would not use pure thinner and a brush..who knows how much is even on there to start with.

Don't re-shoot it with lacquer thinner or more lacquer. You are not going to fix this "problem", trust me. It will just come back. the issue is when the PF was originally sanded, they didn't final sand or use a sealer coat. This means no matter what you do, the wood is still rough sanded. Lacquer will not cover or hide this, the film thickness is not there to allow it. Spraying more lacquer or thinner won't fix it, it will just make it stand out more. Williams was making a commercial product ,not some collector's trailer queen thing.

If you really can't live with it, get a game that has diamond plate. or have this clear coated by a professional with 2 part auto urethane. that is the only solution.

They only made 100 diamondplate BOPs at most, so it's doubtful you have one. (Usually it's Pat Lawlor games in this era that had the sample 100 run of diamondplate. Since this isn't a Lawlor game, they may have not made any diamondplate BOP.) In fact i know you do not have a diamondplate PF, as i can tell from the picture you posted. Also diamondplate examples will say "Diamondplate" and have some LS markings stamped on the face and side edge of the PF wood.

Two things, I agree and said as much with respect to the comment that lacquer will never build a film thickness required to cover the ridges. If thats your problem, or the only part your trying to fix you need to try another method.

However, you started this by saying you also had a bunch of cracks that you wanted to fix. The suggestion I made will in fact fix that. Above post is from a VERY experienced individual- so if they say that re spraying will in fact make the "planking/sanding" marks worse, then I would seriously think about not doing what I said unless its seriously cracked and needs to be delt with. In which case my method will in fact cure the finish and fix the cracks, but it can take a number of coats to do so depending on how deep they are.

Think about what your trying to fix... and maybe you have a two step repair... but clear coats will do a MUCH better job and even they are never going to be the solution to a seriously uneven finish without at least 4-6 coats and none of these products are designed to be put on that thick- they have been used that way on pinball play fields many times and seem to be ok... so think about that avenue seriously. However, really... looking at your game, thats a pretty darn shiny if wrinkled surface... maybe you don't need to fix it at all... its what it is- as stated by cfh- not a piece of art, a game.

100% guarantee they made DP'd BoPs:

http://www.ipdb.org/showpic.pl?id=1502&picno=43591&zoom=1

your picture shows lacquer checking. clean it with magic eraser, and then forget about it. either that or clear coat with a 2 part urethane. that's really the only solution to this. but frankly i don't think it's worth all the worry. It is what it is, as they say. a diamondplated BOP is rare as hens' teeth, so unless you have it done, it's unlikely you'll find one. So if BOP is what you want, you'll pretty much have to deal with this on any BOP (at least to some extent.)

I dont have the knowledge to say about rarity etc... but that looks like a pretty damn nice play field with pretty standard dirt intrusion into some very very fine cracks in the lacquer. cfh is exactly correct, ME and isopropanol will take 99% of that out. Polish, Wax- done! Enjoy.

Don't get your hopes up. Those have been "nearly finished" for almost three years at this point.