I just tried gluing up a quick sample joint using biscuits and RooClear
on 5/8" melamine. The two pieces were about 10"x16", with the joint
along the longer dimension.

The joint was a 90 degree "L" with the edge of one piece joined to the
melamine face of the other. I put the glue on the edge of the one piece
and in both sets of biscuit slots, then clamped the two pieces together
at about the same pressure I would use with yellow glue and plywood. I
left the piece to dry at room temperature for about 18 hrs.

I then tried breaking open the joint for testing purposes. The joint
broke when the biscuits pulled out of the edge (rather than the face),
taking some of the particle board with them.

However, the real problem is that it appears that the
particle-board/melamine bond was basically non-existant (there are no
particles stuck to the melamine).

Anyone have any ideas why it failed? Other comments on this glue have
said that it would pull the melamine off the face rather than fail at
the glue line.

I'm re-trying the joint with no biscuits, just glue. Have to say that
I'm not very impressed so far.

I've emailed the manufacturer to get their comments.

Chris

For best results, biscuits need to be glued with a water based adhesive.


"Chris Friesen" wrote in message
...

I just tried gluing up a quick sample joint using biscuits and RooClear on
5/8" melamine. The two pieces were about 10"x16", with the joint along
the longer dimension.

The joint was a 90 degree "L" with the edge of one piece joined to the
melamine face of the other. I put the glue on the edge of the one piece
and in both sets of biscuit slots, then clamped the two pieces together at
about the same pressure I would use with yellow glue and plywood. I left
the piece to dry at room temperature for about 18 hrs.

I then tried breaking open the joint for testing purposes. The joint
broke when the biscuits pulled out of the edge (rather than the face),
taking some of the particle board with them.

However, the real problem is that it appears that the
particle-board/melamine bond was basically non-existant (there are no
particles stuck to the melamine).

Anyone have any ideas why it failed? Other comments on this glue have
said that it would pull the melamine off the face rather than fail at the
glue line.

I'm re-trying the joint with no biscuits, just glue. Have to say that I'm
not very impressed so far.

I've emailed the manufacturer to get their comments.

Chris

Leon wrote:
For best results, biscuits need to be glued with a water based adhesive.

Roo is water-based, and the biscuits seem to have stuck reasonably well.
(They took chunks of particleboard with them when they pulled out.)

My complaint was that the Roo didn't stick to the melamine (which it is
supposed to do).

Chris

"Chris Friesen" wrote in message
...
Leon wrote:
For best results, biscuits need to be glued with a water based adhesive.

Roo is water-based, and the biscuits seem to have stuck reasonably well.
(They took chunks of particleboard with them when they pulled out.)

My complaint was that the Roo didn't stick to the melamine (which it is
supposed to do).

Chris

I see, I thought it was a Polyurethane glue.
I really have not heard that any water based glue sticks to a non porous
surface like Melamine.

Ok, now I see that you are indeed using the correct glue, I have no idea why
your set up did not work unless you have a gap on the glue line.




I see, I thought it was a Polyurethane glue.
I really have not heard that any water based glue sticks to a non porous
surface like Melamine.

On Mar 27, 1:24 am, Chris Friesen wrote:
Leon wrote:
For best results, biscuits need to be glued with a water based adhesive.

Roo is water-based, and the biscuits seem to have stuck reasonably well.
(They took chunks of particleboard with them when they pulled out.)

My complaint was that the Roo didn't stick to the melamine (which it is
supposed to do).

Chris

In a previous box-building lifetime, I experimented a lot with
melamine joinery. My base material was 5/8 melamine 120 gram both
sides. The '120 gram' is a number indicating the thickness. The higher
the number the better the grade. A good quality shop uses 120. The
dreck you find at RTA-type suppliers is often as low as 60. That makes
a huge difference in how well the melamine itself adheres to the
substrate.
I also made standard L-shaped pieces for testing purposes. My tests
were also taking a close look at how quickly and how accurately a box
could be assembled, without sacrificing the integrity of the box.
Introducing the use of low-root, nibbed screws and ways to hide them.
I tried everything I could think of. I thought the best way was to use
a rabbet or a dado, sunk in only about 1/8". To cut those edges clean
and accurate required way more set-up time than I was prepared to
invest. Scoring blades and dado-stacks are a bitch. PB to PB glues
really well with basic white glue, but now I was clamping. Tried RF
induction, which still required some clamping. Not efficient enough.
Then I tried some lacquer-based adhesives, designed for use with
melamine. Nice results, but only up to a point. That melamine is
attached to the PB with minimal strength. When the joint failed, it
did so catastrophically. No give. Besides, it simply wasn't that
strong. Never did have time for biscuits. Too damned complicated in
production, and PB is PB, no matter what.
Then I tried mechanical fastening. Confirmat screws are very strong,
but offer very little advantage over a #8-2" low-root screw.
Of course, what I got was a very strong joint, but with screw holes.
Solution?
Cover the whole side of the melamine cabinet side with a sheet of PF
PLAM, which you can get in the same texture as melamine. Of course,
you only do that to those cabinets which you can see.
When building oak cabinets, use a sheet of 1/4" veneer ply to cover
your sins.
Hiding your tracks also allows you to shoot nails to hold things in
place while you drill (air drill, they stop nice and quick) 1/8" hole
with a brad-point. Wurth makes nice ones.
Melamine to melamine--- mechanical fasteners. Everything else is a
waste of time.... but that's just my opinion.

r