How to glue wood over varnish finish

[Alan Lightstone]

Long story short, but on a drafting table I'm building, I have an area inside that will still be visible with some pocket hole joinery and a few screw heads that just don't look good visible.

It seems my best solution would be to cover over the pieces of wood with another piece of the same sapele. I would think that wood movement wouldn't be an issue that way either.

The problem - the top and sides of the pieces of wood that will be covered already has several coats of Waterlox varnish on them.

Do I have to sand the pieces down to wood before gluing with Tightbond, or can I just use epoxy to glue the varnish finished wood piece to an unfinished piece of sapele?

[shane lyall]

Epoxy will bond better but not much. It will be a very weak joint if it holds at all. I don't know of any glue that works well over a finish. You need bare wood to get any kind of bond at all and especially with yellow glue.

[Jim Matthews]

Waterlox offers an excellent finish that resists bonding to almost any sticky substance (the reason it's on my dining table, where the five year old eats).

Nothing will stick to this stuff, for very long. If showing hardware is unacceptable, consider dropping in a dowel or two, instead.

[Andrew Pitonyak]

If you are set on that, then you could tack or screw a thin piece to the finished wood and then glue a piece to that.

[russell lusthaus]

Why not varnish them in place like a bung?

Russ

[Alan Lightstone]

If you are set on that, then you could tack or screw a thin piece to the finished wood and then glue a piece to that.

Tacking is an interesting thought. I think from the side it would look bad having a 3/4" piece of wood, a small piece, covered by a larger piece. But could I use epoxy and a headless pinner and have it adhere well? That would certainly hide the seams better (only have one seem instead of two with a thin piece of wood), as well as hiding the real hardware.

[glenn bradley]

If it is purely aesthetic then I would just stick the new piece to the finish with a contact cement or epoxy. You will be gluing to the finish itself and not the material under it but, if this is just a piece of trim for appearances, I would be OK with it.

[JohnT Fitzgerald]

If it is purely aesthetic then I would just stick the new piece to the finish with a contact cement or epoxy. You will be gluing to the finish itself and not the material under it but, if this is just a piece of trim for appearances, I would be OK with it.


+1

3M makes some pretty good spray adhesives.

Another option, if it's pocket jointery holes and screws that are visible, is to use appopriately sized plugs. You can buy them, but I would think you could use a normal dowel with glue, and then use a flush-cut saw to cut it flush to the surface.

[Alan Lightstone]

+1

3M makes some pretty good spray adhesives.

Another option, if it's pocket jointery holes and screws that are visible, is to use appopriately sized plugs. You can buy them, but I would think you could use a normal dowel with glue, and then use a flush-cut saw to cut it flush to the surface.

I have put plugs in them. Unfortunately, the plugs are maple, and dyeing and varnishing the plugs still yields an unsightly plug. Also, there are a few screws in that piece. Those are the only visible hardware on the entire drafting table, and I'd definitely like them to vanish.

[Alan Lightstone]

If it is purely aesthetic then I would just stick the new piece to the finish with a contact cement or epoxy. You will be gluing to the finish itself and not the material under it but, if this is just a piece of trim for appearances, I would be OK with it.
It is purely aesthetic. The pieces will have no stress on them, bear no weight. They are just there to cover the pocket screw plugs and screws.

Do you think I should make the covering pieces of wood 3/4" (roughly the size of the wood they are covering), or should I make them thinner (down to veneer size if I need to test my resawing skills again).

[Sam Murdoch]

Thin wood doesn't glue well as it wants to twist or deform. I would say nothing thinner than 3/8" thick. Why glue? Why not just use some wire brads or headless pins, then the Waterlox top coat will "lox" the trim pieces in place.

[Paul DeCarlo]

Why can't you scrape away some of the finish to bare wood where the trim will go? A cabinet scraper, small paint scraper, or even a chisel or plane iron would work. You wouldn't need much overall glue surface for a decorative piece.

[Larry Edgerton]

I keep Kangaroo Glue around for just such an occasion. Its actually made to glue Melamine, but works very well on finished surfaces.

Larry

[Cary Falk]

100% pure silicone caulk works great for holding things in place.

[Alan Lightstone]

Present game plan is to sand the top of the pieces mostly down to wood (don't really need 100%, just some bare wood to bare wood contact), and cover over them with 1/2" pieces of sapele. I recessed them, and they look like an intentional design element. I'll glue them and pin them with my 23ga headless nailer. Then lots and lots of coats of varnish, and I'll be back on track.