Replies

1. 
   saschafer | Jan 02, 2008 09:05pm | #1

   1) Yes, you should apply veneer to both sides. It doesn't have to be the same kind of veneer, but it should be approximately the same thickness.

   2) The "best" way to attach veneer to a large surface is probably to use a hard urea or phenolic resin glue (e.g., Unibond) and a veneer press (either mechanical or vacuum). But you should be able to get good results by rolling on ordinary yellow PVA glue (e.g., Titebond) to both surfaces, letting it dry, and then "ironing on" the veneer. You have to be careful to apply a uniform layer of glue and avoid getting any foreign objects trapped in it.

   3) You can get vinyl edging from Rockler, among other places. Typically, it's installed by sawing or routing one or more narrow grooves in the edge of the piece; the edging has barbed flanges that fit in the groove and hold via friction.

   -Steve

    

1. 
   stained | Jan 04, 2008 02:22am | #2

   how much would a 1" thick piece of MDF warp with a thin sheet of veneer glued to it (if I only glued top) ? And the 1" thick MDF will be secured to legs.

   Edited 1/3/2008 6:23 pm ET by stained

1. 
   user-83153 | Jan 04, 2008 03:02am | #3

   There isn't really any way to guess. If you are making it a full sheet, I would say quite a bit. I used the type of veneer (paper backed) you are using when I first started on 3/4" MDF without using a balance veneer and a 12" x 20" door warped almost 1/2" over a 6 month period.

   If you use unbacked veneer you can use a cheap veneer for a balance piece. That is one of the drawbacks of using the paper backed rolls, you can't get any of that stuff cheap. I don't know how it would work if you tried to use an unbacked balance veneer with a paper backed face veneer.

                    Rob

1. 
   WillGeorge | Jan 04, 2008 08:57pm | #6

   Bob..Not knocking what you posted at all but I was wondering (as I usually do). MDF does not expand contract like solid wood does. SO.. If you veneer one side and it is firmly attached to something would it still do that. I have no idea BUT my brain tells me NO? (Not a well formed brain here)

   Edited 1/4/2008 12:57 pm by WillGeorge

1. 
   user-83153 | Jan 05, 2008 01:34am | #8

   Will,

   It is my understanding that it isn't the substrate that causes or eliminates the warping, but the veneer itself, which is a solid wood, albeit a thin piece of solid wood. When you use a water based glue to attach the veneer to the substrate the veneer gets quite wet. It will expand initially and then shrink as it dries over the next day or two. This will cause immediate problems with cupping, warping, etc. before the construction process can even be completed.

   I am sure that if the substrate were confined in its ability to move by securing it well enough to whatever, you could keep it flat. I don't think that in a normal piece of furniture you could secure it well enough or fast enough to accomplish this though. IMO you are always fighting a losing battle if you attempt to stop wood, even a thin piece of wood from moving where it wants to. Unless you use another piece of wood to accomplish the task for you. That is what the balance veneer is for. It theoretically supplies an even and equal force in the opposite direction that the face veneer wants to move the substrate.

                   Rob

2. 
   JohnWW | Jan 05, 2008 02:12am | #9

   MDF does expand and contract but only about half as much as a typical solid wood under the same conditions.  It also moves in all three dimensions since it is grain free.

   John White

3. 
   WillGeorge | Jan 08, 2008 07:44pm | #11

   Rob A. and JohnWW..Thanks for the response and sorry for the delay in my response. It took me awhile to collect my data. 'Data' is my measurements of projects I have made. These measurements are on the finished project compared to my original notes before starting a project. I do try to cut, Etc. to my original notes but I will often change things as I work.My comments are out of context with "Gluing 4x8 sheet of veneer to MDF" but I thought it fits a question I have always had.I often use veneered plywood or MDF in a project. Cost is the reason. I have estimated costs for a particular project using all 'solid' wood verses plywood / MDF and solid woods. I find that I can use the ply or MDF (even mixed core types on the same project) at MUCH LESS cost and I can then afford to use premium 'solid' wood for face trim and other important 'visual' aspects.I also use MDF for all my patterns and all of my several different uses router tables. I have never found a problem with MDF moving unless I do something stupid like putting a wet bottom 'coffee' or whatever cup down on the surface and leaves a raised ring that matches the bottom of the wet object set down on it.Yes I realize that ANY WOOD moves to some extent as JohnWW posted. (I'm sure he is a heck of alot smarter on the subject than I am!)By the way JohnWW, I assume you are the maker of that New-Fangled Workbench, Revisited. Take a look at this well-engineered workbench that's as versatile as a Swiss Army Knife...I am well engineered also but not as Cool or Sharp as a Swiss Army Knife.. Hell, I'd cut off a finger just opening it much less closing it! ... :>) I love the bench and will make it this summer!Geee.. I got distracted.. I do that ALOT!My shop is unheated and winter time projects here in Chicago area are sort of limited. Cold and Wet. Summer hot and humid! OK so yesterday it was 65 or so...Amazing!Anyway, to get on with what I started.. I trim all my Ply/MDF in solid wood (1/2 to 3/4 inch) with mitered corners for the face trim for the 'exposed' edges. I usually use Titebond or Gorilla glue.Many times I will use a Lock Miter Bit for the carcass 'box' edges.I have never had a miter joint crack (open up) from the ply or MDF expanding or contracting. At least that I know of...My fixtures stay flat and true and I only shellac the MDF exposed edges and try to remember to keep all surfaces waxed on occasion. All my fixtures stay in my unheated shop and they seem to stay as they were when made or at least very close to it! I DO check them for flatness before an important project.. (Not used much in the winter)..Any comments?

   Edited 1/8/2008 11:49 am by WillGeorge

2. 
   saschafer | Jan 04, 2008 07:18am | #5

   "how much would a 1" thick piece of MDF warp with a thin sheet of veneer glued to it (if I only glued top) ?"

   If it were me, enough to keep me up at night.

   -Steve

    

1. 
   Ron01960 | Jan 04, 2008 09:04pm | #7

   I'm going to say this as pain less as possible. Find some one in your area who has a vacuum bag and the experience. 4x8 is a very large size. Speak with them. You won't be sorry. You can order high quality ply & MDF already veneered both sides. Put your attention into other parts of the table. In the future you should start out veneering with smaller sizes, 4x8 may be to large for almost every one who has a bag set up. I always cut my sheet goods into smaller sizes, more manageable, easier to match. No ruptured discs or strained back.best of luck
   Ron

2. 
   GDH2 | Jan 04, 2008 05:18am | #4

   There are lots of special edging options. One simple and effective option is T-edging in plastic, rubber, aluminum, etc. You cut a slot in your surface edge. The moulding has a tongue usually with barbs.

   If you're interested, just Google T-edging or T-molding. Good luck!

3. 
   md2453 | Jan 07, 2008 06:16am | #10

   Stained:

   You've received some very good advice so far and I can only add that if this is a one shot project you'd be better served to use a sheet of cabinet grade plywood or preveneered MDF,  as someone pointed out that way you can focus your attention to the building of your project.

   On the other hand if you are going to veneer more in the future, I'd suggest you buy or build a vacuum pump and a vinyl bag large enough to hold the largest piece of material you envision working with.  A little time spent researching vacuum veneering will yield a wealth of information on building the needed equipment or buying it.

    Try looking around on this web site http://www.joewoodworker.com they've got some information on building a nice vacuum pump and bags.

   I work with veneer a lot in my business and would suggest also that you use solid wood veneer rather than the paper backed veneer you mention.  The unbacked wood veneer is thicker and in my opinion much easier to work with.  I've purchased veneer from http://www.certainlywood.com for years and have always had great results!

   Enjoy,

   Madison