What damaged my tabletop and how do I fix it?

[PitonView]

Probably not a water ring with Arm-R-Seal - but mayonnaise is easy to try and will clean up easily if it does not work!  Thanks for the idea.

[Cooler]

Could it be a water ring?  Try an old trick ... put a dab of mayonnaise on your finger tip and rub it in and then buff it with a soft rag. I always pooh-poohed that remedy .... until I tried it on my granddaughter's oak table. Six months later I still can't find the ring.

Mayonnaise is about 90% vegetable oil, and has the advantage that it does not run.  So anything oil will resolve, the mayo will also with the advantage that it does not run and you can wipe it up with a slice of bread and make a sandwich.

[PitonView]

Probably not a water ring with Arm-R-Seal - but mayonnaise is easy to try and will clean up easily if it does not work!  Thanks for the idea.

[Cooler]

If you ever get one of those "Do not park here ever again, you moron" stickers on your windshield, don't try to scrape it off.  It will take forever.  The adhesive is very aggressive and the paper is of such poor quality that it falls apart.

Instead slather on some mayonnaise all over the sticker.  Leave it overnight and come back with a towel and wipe off the label.  This won't work with labels made from high quality paper as the oil will not be well absorbed, but the paper they use for those labels are basically newsprint.  So it works for that.

Also, if you've removed some double sided tape from your dashboard or other surface, leave some mayo on it over night and wipe off the remaining adhesive.  
This is a very safe approach.  (Although an environment heavy in mayo can elevate your cholesterol levels.)

[cvillewood]

I had a guest put a full to the top hot cup of coffee on a table (finished with Waterlox i think) and of course it spilled a bit when it was put down, and left there for a bit. Burned a ring just like yours but of course mine is coffee cup sized.

[jteneyck]

I had a guest put a full to the top hot cup of coffee on a table (finished with Waterlox i think) and of course it spilled a bit when it was put down, and left there for a bit. Burned a ring just like yours but of course mine is coffee cup sized.

I think the finish was something other than Waterlox or your guest was lying about what was in the cup.  I've never used Waterlox, but if it's anything like Arm-R-Seal a cup of hot coffee won't damage it no matter how long the spill is left there.  And it won't burn unless the cup is really hot, like over 300°.  Sounds more like an uncatalyzed lacquer finish. 

John

[cvillewood]

John, it was either Waterlox or Arm-R-Seal.  I see Waterlox says boiling water won't harm it, and ARS says to "Protect from heat", so I'm guessing it was ARS.

[Haryo]

Maybe no one here will appreciate this, but I make nice things, and yet I don't care at all if they get rings or burns or scratches. In my family we were always scolded for not using a coaster under a glass, and maybe I'm just rebelling against that upbringing. The wood is fine, the rest of the finish is fine, and it can always be refinished. To me these are just marks of use. It is nice to see that over many years the items you make have gotten a lot of use. Really, just another bit of character imparted to the piece. Don't sweat it.

[Cooler]

I had a guest put a full to the top hot cup of coffee on a table (finished with Waterlox i think) and of course it spilled a bit when it was put down, and left there for a bit. Burned a ring just like yours but of course mine is coffee cup sized.

I put a cup of boiling water on a butcher block counter that I finished with Minwax Oil, semi-gloss.  It left a ghost of the bottom of the cup when I picked it up.  After about a week it faded away.  I am assuming it picked up some moisture, but all I know for sure is that it "self-healed" in this case.

[PitonView]

I've always used orange oil to dissolve the glue and leave a nice smell.