kitchen worktop joint glue - surprising result

[Matt@]

I'm doing our kitchen, I've a woodwork related background but have only ever fitted one kitchen in my whole life...

Its a horseshoe kitchen so needed the laminate worktop corners with masons mitres which I've done myself. The joints bolt together dry perfectly so got that bit right :roll:

So I'm trawling google to find best way of gluing/ fixing the joints and everyone swears blind their way is best - silicone, exterior PVA, colorfill, cascamite etc

I thought I'd do a test so glued (with bolts) up 3 small test pieces using silicone, blue PVA and cascamite. After the glue had set overnight I pooled water over an area of the the joint for 12 hrs to see which stood up best to water ingress and blowing etc and had some surprising results...

Silicone (Dow Corning 785)
spread silicone beads on both faces and bolted up. Couldnt get surfaces dead level at all. The silicone seemed to bunch up a bit and stop the joint closing neatly. Water test = no difference.

Cascamite (mixed quite thin)
cramped up lovely, dead flat joint with no step. Water test = slight swelling to edges to both sides of joint

Exterior PVA (blue)
cramped up nearly as good as cascamite but may have overtightened as very minute lumpyness to areas of the joint. Water test - no difference.

So to summarise I was surprised, as I thought cascamite in gluing up best and being waterproof would be the best way but it was the worst!

Didnt try Colorfill as put off by limited open time.

Its looking like Blue PVA for my joints unless anyone can persuade me different and as to how people use silicone and get a nice job is beyond me unless I was doing it wrong....Glad I did this test as was going to use silicone!!!

 

[NazNomad]

I know mine used Colorfill (I didn't fit the kitchen though - in 2002) and there have been no problems.

 

[sploo]

Horseshoe... so end grain to long grain right? You really don't want to be using an actual glue with that; the differential movement in the end grain will be much more than the long grain. Unless you're talking about a man made board rather than solid wood, in which case ignore me!

 

[Matt@]

yes laminated board not solid...

 

[RobinBHM]

silicone needs spreading very thinly, its viscous to squeeze out much -which its disadvantage.

maybe end grain sealer, which is like runny wall paper paste, we use it to seal end grain of joinery before painting or to seal ends of cills on site.

https://www.reddiseals.com/product/end- ... AsOc8P8HAQ

I can see D4 pva working quite well, its not too thick and it will soak into the chipboard quite well.

 

[sploo]

yes laminated board not solid...

I'll get my coat then

 

[MotamJoinery]

when I did my kitchen I ended up using colourfill on the top and a line of titebond 3 on the bottom which seemed to work very well. year on and no issues so far.

 

[meccarroll]

I have always used pva glue, either waterproof or not because most of the worktops that I have fit have been on contract work for clients supplying the materials (inc pva for worktop).

If your joint is spot on no water will penetrate the joint but if you have slight gaps then it will.

Cascamite glue should be as good as PVA for the joint the only reason I can see the Cascamite joint is failing is because water has penetrated through a gap in the joint where it is too wide, it's very unlikely to be because you used Cascamite.

Most worktops are chipboard which is very absorbent so should first have a primer coat of glue to seal the curt edges before gluing.

Mark

 

[Lons]

when I did my kitchen I ended up using colourfill on the top and a line of titebond 3 on the bottom which seemed to work very well. year on and no issues so far.

I always did the same. Colourfil top bead and Titebond exterior glue along the rest of the joint. I glued both surfaces and made certain the colourfill sealed the joint completely with no gaps. Never had a single call back in 18 years of fitting.

Bob

 

[Matt@]

I did it with blue PVA in the end, worked fine. Re. the cascamite I used, the join was spot on but still laminate still raised slightly both sides along the join. I'm wondering if this was due to over tightening and the cascamite being very thin, odd it should happen after the water sitting on it and not after bolting together....

On a side note, I can now see why good fitters earn good money!!!