Glue over poly

[Mike Cogswell]

Well, I just pulled a bonehead move!

I'm making a set of furniture for my soon to be born granddaughter's nursery. I'm doing the dresser first so my daughter can "nest" setting up the nursery and also use it for a changing table.

In order to control squeeze out, I decided to prefinish the sides of the carcass and the legs, carefully masking off the areas that would be glued. At least that was the plan. The sides are masked for the legs and the moldings at the top and bottom, but I totally forgot there is going to be a strip of horizontal moulding part way down the side. <sigh>

The side has one coat of Minwax fast drying poly, applied with a brush and wiped off after 10 minutes. There are horizontal dividers internally, so brads into the moulding from inside are out. I'd really like to not use them externally, but I don't know if I can get decent adhesion to the poly with glue.

Any and all ideas or suggestions gratefully accepted.

Thanks, Mike

[Kent A Bathurst]

Put down masking tape along the track of the molding - and make the gap a bit too narrow.

Get a block of wood narrow enough to fit that gap.

60g sandpaper will put paid to that one coat of poly pretty quickly.

[John TenEyck]

What Kent said. OR, you could route a small dovetail in the side after finishing and do a real high end job of installing the molding. OR, put a couple of pan head screws in the side, route a couple of matching keyhole slots in the back of the molding, and install it that way. Several options. In any case, if the cabinet sides are solid wood you don't want to glue that molding on, except maybe a couple of inches at the front.

John

[Kent A Bathurst]

if the cabinet sides are solid wood you don't want to glue that molding on, except maybe a couple of inches at the front.

John

Yeah - what J10 said - I didn't think it thru. Glue the first few inches, and then a few brads after that - they will bend with seasonal movement.


Or - the dovetails if you really want to do a class job.

[John TenEyck]

Which reminds me - I remember seeing an article where the guy screwed a small male dovetail piece, about 2 - 3" long, to the front edge, middle and back edge of the cabinet side. Then he routed a matching female DT in the molding. Slid the molding on and glued it at the front edge. Very nice.

John

[Steve Baumgartner]

John, I don't remember where (maybe FWW?) but I also saw that article and have done edge moldings that way ever since. Here's the process I follow (I've described all the steps in detail. This really doesn't take as long as it might sound!):

- Choose a dovetail bit that will make a decent sized slot in the molding without cutting through the profile or leaving areas so thin they are weak. Mount this bit in the router table and set the depth and fence appropriately for the molding. The precise depth and placement are not critical so long as they don't create weak spots. It is not necessary for the slot to be very deep - around 1/4 inch is plenty.
- Rout or saw a rectangular dado slot in the back of the molding slightly narrower and shallower than the dovetail bit. This removes most of the material and makes it easier for the dovetail bit to cut cleanly.
- Rout the female slot in the back of the molding. It is usually easier to cut this slot before shaping the profile of the molding because it leaves a flat reference surface whereas the profile does not. The critical technique is to keep the molding pressed firmly down and against the fence during the cut. Use push sticks and hold-downs to keep your fingers safe.
- Next make a second female test piece with a slot infinitesimally wider but the same depth. Use the same setup on the router table, just cut once and then move the fence the smallest increment you can.
- For the male part, you need a board that is thicker than the widest part of the female slot. The exact thickness isn't crucial, though there's no point in wasting wood. You will rip the tail off this piece later, so it should be wide enough that you can easily hold it while routing and sawing. This piece won't be visible, so the kind of wood doesn't matter.
- To cut the male tails, first raise the router bit by 1/16 inch or so. Place the fence so that the bit just cuts down to the bottom edge of the board, making a sharp corner there. Rout both sides of the board to create the tail shape. Test the fit into your sample slot. In all likelihood it will not go at all yet. Adjust the fence away from the router bit a tad and repeat the cuts on both sides. Repeat this until the tail will almost but not quite slide into the test board slot. Then continue, but only cut one side because doing both sides doubles the amount removed and you are now trying to fine tune! Repeat until the tail will slide easily but not sloppily into the test slot. This will give you a tail that slides tightly into the real slot.
- Adjust the table saw fence and rip the tail off the edge of the board ever so slightly taller than the depth of the slot.
- Slide the tail into the test slot. If you did the previous step right, a tiny amount should stick above the surface. Plane or sand this off until it is flush.
- Cut the tail into pieces about 2 inches long.
- To attach the tails to the top, start by pushing one partway into the forward end of the molding. Clamp the molding to the edge of the top, flush with the surface. Drill a countersunk pilot hole through the tail into the edge of the top. Drive a small screw through this hole, making sure that the end of the screw is flush or slightly below the surface of the tail.
- Pull the molding toward the rear until the tail almost emerges from it and reclamp flush. Repeat the drill and screw process.
- Repeat the previous two steps with an additional two sections of tail and the middle and rear of the top (the rear one is a bit trickier to clamp in place).
- To install the molding, leave it a bit long with a square end at the rear and a miter at the front. Put glue ONLY on the front-most tail and the miter face of the other molding; do not put any glue in the dovetail slot. Slide the molding onto the tails from the rear. It should be a fairly tight fit but not so tight that you can't tap it forward with a small hammer. As it approaches home, tap carefully until the front miter is just closed. If you drive it too far forward, the best way to push it back is to put clamps front to back and side to side across the top and tighten them so that the slopes of the miter forces the molding to slide back.
- Saw off the excess flush with the back edge of the top.

Steve

[Mike Cogswell]

Thanks for the ideas. The sides are 3/4" furniture grade hard maple plywood, so I don't expect movement.

[John TenEyck]

Thanks for the details Steve. I believe the article was in FWW, as you suggested.

John

[Kent A Bathurst]

Thanks for the ideas. The sides are 3/4" furniture grade hard maple plywood, so I don't expect movement.

Sand it. Glue it. Next problem.

[Rich Engelhardt]

Sand it. Glue it. Next problem.

That - or - use a different adhesive.
It's molding and not structural right?
Brush a liberal coat of poly on and bed the molding in the wet poly and use that as the adhesive.
I do that all the time with decorative or trim pieces.

Contact cement would work fine though.

Steve's solution though is arguably the most appropriate for woodworking.