The underside of a project

[Chet]

I have never put as many coats of finish on the underside of a project as I do to visible areas.  Projects like like tables.  But I have started to wonder if this is incorrect.  What do you generally do.

[JerrySats]

Curious to see what others are doing for tables and such . I at least do put something on the underside to just seal the wood .  How ever in looking over old furniture I rarely see the insides or undersides of anything finished .  

[RichardA]

I finish every inch, to protect from the weather changes in any house. However, I do add more protection to areas that are visable and useable.  It's called CYA, it cuts down on returns or repairs.

[AceHoleInOne]

I give the underside of table tops, tops in general, 1 fairly good wet coat maybe 2. Inside of case work....just a quick spray.

 

-Ace- 

[wtnhighlander]

I coat every surface at least once, usually with shellac for surfaces that don't need tougher protection. Shellac dries fast.

[wdwerker]

I give undersides and insides at least 2 coats, backs a might only get one wet coat, everything else gets minimum 3 coats, 2 sands between.

[Shane Jimerfield]

This is not specific to table tops, but I was just reading an article by Tage Frid (FWW, Jan/Feb 1991, pg 85) he says,

 

"Finishing—I finished both chests with Watco oil. Never finish the inside of the carcase or outside of the drawer sides, because they may stick together. Instead, rub them with paraffin. And never use an oil finish on the inside of the drawers, because it always bleeds and may spoil what is inside. Instead, you can seal the drawers' insides with shellac or lacquer. You needn't worry about moisture inside the chest, however, because the drawers are closed most of the time."

 

For some context. In this article he is talking specifically about his 4 drawer chest. He does not use and kind of mechanical drawer slides - he does it the old-fashioned way, wood on wood. Which for fine furniture is the preferred method.

[dwacker]

This is not specific to table tops, but I was just reading an article by Tage Frid (FWW, Jan/Feb 1991, pg 85) he says,

 

"Finishing—I finished both chests with Watco oil. Never finish the inside of the carcase or outside of the drawer sides, because they may stick together. Instead, rub them with paraffin. And never use an oil finish on the inside of the drawers, because it always bleeds and may spoil what is inside. Instead, you can seal the drawers' insides with shellac or lacquer. You needn't worry about moisture inside the chest, however, because the drawers are closed most of the time."

 

For some context. In this article he is talking specifically about his 4 drawer chest. He does not use and kind of mechanical drawer slides - he does it the old-fashioned way, wood on wood. Which for fine furniture is the preferred method.

 

I would agree with this for the most part. For years we never finished even the inside of kitchen cabinet drawer boxes. Today they come pre finished with a UV finish but in reality its just marketing for cabinet makers.

[TerryMcK]

Finishing the underside shows that you are paying attention to detail. I give it a couple of coats as do insides. However everywhere else would get 4 coats and tops another one or two - 1 sealer coat (shellac) all over, 3 top coats of finish and 4/5 coats on tops. Backs would also get 3 as you never know what the end user will do with the cabinet. I have seen cabinets used as room dividers where the backside is seen even though they were originally intended to go against a wall. So pay as much attention to the back as you do the front.

Edges of table tops undersides need 3 top coats too even if you don't nib sand as much towards the middle as people have a tendancy to "feel the quality". Rough to the touch edges turn peoples opinions.

[CessnaPilotBarry]

I do a coat or two to the bottom, but I don't go crazy...   It helps with gum removal. 

[dwacker]

But it does make them a little easier to clean up.... for when I spill an entire pot of coffee and half of it ends up in the silverware drawer

 

This I agree with but it does nothing for wood stability or anything of that nature. Its just another selling feature. Melamine is the top seller now days for this very reason. Its easy to clean and adds perceived value. Just like 3/4" plywood boxes its all marketing, "look at mine they have ply 3/4" boxes" no "look at mine they have 3/4" plywood boxes with melamine" Finishing things like the full underside of a table or the inside of a dresser doesn't really add any marketing value or any quality. 

[ResidentEvil]

For table tops specifically, I've always heard to put the same number of coats on the bottom as you do on the top.  It's not going to prevent moisture changes in the wood, but it will help make sure that moisture changes at an equal rate from all sides.  Supposedly it helps reduce warping/cupping since one surface isn't transferring moisture at a faster rate than another.

 

Being pretty new to the game, I dont know how much water this theory holds (pardon the pun) but it makes sense.  Also dont know if there is a point of diminishing returns based on the # of coats.  If you do 4 on the top is 2 on the bottom enough to stabilize moisture transfer?  No idea.

 

But I have played it safe and applied the same # of coats to both the top and bottom in the pieces I've done.  I do save time on the bottom during sanding in between coats.  Much less thorough sanding on the bottoms between coats than the top.