safe "dirt" removal

[EricBruns]

I recently brought home a nice desk that has some age on it. It also has some residual human/organic dirt on the front edge I'm guessing where the owner leaned and laid his arms? 

What is the safest method to remove and preserve as much of the finish as possible? Thanks!

[rayknight]

My guess is this is shellac.  I have seen this occur on front edges of desk. can diagnose & fix by rubbing out with alcohol (solvent for sheLlac).  If it softens & moves it is shellac, you can smooth it out until it blends & be done, or fully remove & re-shellac.  I have done the first. If it doesn't soften, it is some other finish & you might need mechanical removal prior to refinish.  await input from real experts.
Ray

[Willyou]

I'm not an expert either. However, I think you can safely use some mineral spirits on that edge first to see if it will remove the dirt. What ever finish is underneath won't be harmed and you may not need to do anything further.

[jteneyck]

Sweat and oils often soften the finish and make an easy repair impossible.  But maybe you'll get lucky and find that it's just dirt.  I would start with mineral spirtis, as Willyou suggested, and see how much comes off.  It won't harm shellac or most any other finish.  If that doesn't take off all the dirt, then try a little dish soap in warm water.  Between the two of them you should be able to remove all the oil and water-soluble dirt and oils.  What it looks like after it's cleaned will determine how best to proceed.  

John

[EricBruns]

Sweat and oils often soften the finish and make an easy repair impossible.  But maybe you'll get lucky and find that it's just dirt.  I would start with mineral spirtis, as Willyou suggested, and see how much comes off.  It won't harm shellac or most any other finish.  If that doesn't take off all the dirt, then try a little dish soap in warm water.  Between the two of them you should be able to remove all the oil and water-soluble dirt and oils.  What it looks like after it's cleaned will determine how best to proceed.  

John

Thanks guys - will get some mineral spirits after it in the morning and will report back!

[Terry W]

I recently brought home a nice desk that has some age on it. It also has some residual human/organic dirt on the front edge I'm guessing where the owner leaned and laid his arms? 

What is the safest method to remove and preserve as much of the finish as possible? Thanks!

Many years ago we brought home two very old Stickley dressers that once belonged to my wife's grandparents.  They both were covered with the same type of dirt, sweat and body oil residue. It looked so bad that no one else in the family wanted them. A local antique dealer told me his secret for restoring the finish on pieces like this.
He said to use GOJO Natural Orange Hand Soap without Pumice.  It worked like a champ. Using LOTS of paper towels, years of grease and grime came off without harming the original finish. When it's all clean, wipe off as much as you can and follow up with a mild soap to remove any residue.

They both now reside in our bedroom and still look great.

[adamcherubini]

Your best bet is to always start with a 10% solution of household ammonia. Ammonia is an awesome cleaner degreaser that leaves nothing behind. We should use it for all household cleaning. Mineral spirits, pretty much all petro -chemicals leave oily residues behind that can cause other problems. Ammonia is what they use in museums to carefully remove grime.

[Roly]

Your best bet is to always start with a 10% solution of household ammonia. Ammonia is an awesome cleaner degreaser that leaves nothing behind. We should use it for all household cleaning.  Mineral spirits, pretty much all petro -chemicals leave oily residues behind that can cause other problems. Ammonia is what they use in museums to carefully remove grime.

Ammonia is not safe for shellac.   Works good to remove shellac.  Roly

[Admiral]

If other suggestions don't work, try TSP, sold in paint stores, it is a fabulous "human oil" degreaser, I've never used it on finishes, so test somewhere else first. Use gloves as it irritates skin, a lot.

Oh, "trisodium phosphate"  https://www.amazon.com/Savogran-10621-Tr...=1-22&th=1