contact cement for solid shelf edging

[igor]

Rather than clamping or nailing shelf edging 'til the yellow glue sets up, what about contact cement? I know that the wood cannot be repositioned -- thus the word "contact". I am thinking of a wood edge rather than edge tape. For 3/4" ply, I'd use a 1/4" thick slice of 5/4 and then route the part that overhangs above and below the ply. WIll contact cement hold as well as yellow glue and clamping?

A concern is that staining might be a problem if there is any squeeze-out/drip onto the ply. I haven't used contact cement in a while and don't recall if it is possible to roll some on the edge of the ply w/o it unavoidably ending up on the surface of the ply.

Comments? TIA. -- Igor

[Chuck Hoffman]

Yellow carpenter's glue sets up in about an hour. By the time you wait around for the contact cement to get dry to the touch on both surfaces, the time differential is not great.

Besides, I'd bet carpenter's glue holds better than contact cement. I'm constantly having to re-fit pieces of high pressure laminate on countertop edges because the contact cement failed.

[Bob]

It won't be as strong and secure as yellow glue. Try using painter's masking tape to hold the wood edging in place. I'm not Mr. Krenov, but its worked well for me - found it on one of those woodworking tips pages.

Bob

[Larry Jaques]

On Thu, 18 Nov 2004 18:04:59 GMT, "Chuck Hoffman" calmly ranted:

If that's the case, you either:

1) Didn't clean the parts prior to gluing 2) Didn't use the proper material to bond to 3) Didn't use enough cement, or enough coats on some mat'ls 4) Didn't wait the proper time for tacking (longer in humidity) 5) Didn't ventilate the area properly during tack time 6) Used the adhesive at too cold a temperature for proper bond 7) Didn't really smack the two surfaces together and clamp for a short while afterward to ensure a good, firm, complete bond 8) Used adhesive beyond its date or had been otherwise corrupted OR 8) Any combinations of the above.

Glues don't "just fail", guys. We have to help 'em fail. DAMHIKT

[Al Holstein]

I have used contact coment for gluing solid word trim to plywood for the last 25 years and have never had any of the edges come off. I used solid word to cut my trim and glue to to 3/4 or 1/2 plywood and router of the edges that extend on both sides. Normal 1 inch solid is just a bit wider that 3/4 ply. A little scraping and sanding and the edge looks like the edge of solid wood. I have used bits for trimming formica with either a straight or a bevel. I prefer the bevel bit.

It works,

Al

[igor]

Since you have had such success with this, could you provide some details about how you do this?

For example: What kind of applications have you done this in -- such as book shelves, drawers? How do you apply the cement to the edges - to get enough but avoid runs? How do you deal with any runs or squeeze-out, if there is any? Have you ever stained the wood afterwards and are there any problems of the stain not taking at/near the joint? Any tricks to getting things aligned before contact - since, unlike with an oversized piece of laminate, there is less margin of error?

How thick/deep is the wood you use on the edge? AND, do you clamp the trim to the ply?

Before I made the original post I thought I knew the answer to most of these, but since a number of replies indicated that this approach would NOT work well, I thought I'd ask even some simple ones to make sure I don't miss anything. TIA. -- Igor

[Mike Marlow]

The good news is that contact cement is not glue, so you don't have all of the glue issues to deal with. No squeeze out, no clamping, no runs. Stain would likely still be an issue, but just don't overdue the contact cement. With contact cement, you're just looking to coat each surface then let it tack. Though... remember, once on, always on. You don't adjust pieces after you've placed them with contact cement.

[Al Holstein]

Igor,

I use DAP contact cement. The trim pieces that I use are ripped about

1/8" to 3/16" thick. I have used red oak when I am using oak ply wood, I have also used in on birch plywood for kitchen cabinet shelves. I did all of the shelves and drawer sides for the kitchen cabinets that I built.

I use a 1" cheap bristle brush and liberally coat the plywood and the trim. You let it dry to the touch (15 minutes or so) and then put the two pieces together. I then hammer the trim edge down to really make the two pieces to really bond together. I use a rubber hammer to avoid denting the trip pieces. With this you are left with a small amount of trim that lips out over the edge of the 3/4 plywood. It is right that you have to get the piece on correctly as you can't move it after you place to gether. I then trim the shelf by running it vertically on my router table. Using a bearing formica trimming bit you cut of the extra edge and have a flush clean edge. The contact cement that may drip down on either piece is fairly easy to remove with a bit of sanding. I don't think that it makes as big a mess as glue or causes as much problem with staining.

It may not be as strong a joint as glue makes, but if you don't have any expose edges the trim piece is practially impossible to remove.

The only problem that I have had is splitting a piece of trim when routing the excess off. This is either a result of trying to take too much of in one cut or a section of bad grain on the trim piece. I have never had a piece come off with time or use.

Good Luck!

[igor]

Al -- Excellent! That detail is _very_ helpful. For drawer sides I may use 1/4" thick strips on 1/2" ply and then using a 1/2" bullnose. Doing 4' or 8' strips at one time should go reasonably fast. And if I use a lock miter bit for the drawer joints, it should all fit fine. Again, thanks. -- Igor

[Al Holstein]

Igor,

A couple of suggestions. Doing 8' at at time may save some time, but it will be more difficult to control the trim piece and get it lined up correctly to make it stick. I do spend some extra time triming each piece to length rather than doing it batch fashing like you suggeste.

Good luck and let me know how it comes out.

Regards,

Al

[igor]

Al -- I will post results but it may be some many months. I was asking now mostly just to decide for my much-delayed kitchen project whether/how I can use ply for the drawers or whether I would need to use solid wood to get the look I want. As for the length of the wood to edge at any one time, that is a good point and I will probably start with 4' lengths -- and may stay there. I do also work with plastic and have strips to which glue doesn't stick, so I am thinking posibly about a jig, especially if I do longer than 4'. -- Igor