Glueing lacquered solid wood?

[al4567]

My flooring has been delivered, and is lovely indeed, can't wait to get it laid, but....... the lacquer extends right over both the tongue and the grooved edges, down to the base thereby sealing the porosity of the glueing area which is what PVA glues rely upon for bonding!
So... what are my options?

Abrade every tongue and groove before glueing!(hope not!)?
Use a different adhesive for the job?
Use the PVA and expect it to work like mortar for bricks(wouldn't have thought so)?

 

[WoodYouLike]

Nice quality
How wide are your boards again? (And if random lengths, how many % is short)?

 

[al4567]

I don't have them in front of me right now, but from memory they are 910mm by 122mm.
They are all full length at 910mm.

Today I have joined a short test-piece with PVA to see what the bond is like on the lacquer. However looking more closely at it, I realise I can sand the mating faces of the tongue and groove without too much difficulty. Only the upper butting joint between boards, and the upper and lower surfaces of the tongue are machined to be a mating surface. The rest appears to be cut for clearance(for excess glue?)
I think I can make a shaped sanding tool quite easily to do this.

 

[WoodYouLike]

don't take me wrong, but are they 910mm long or wide?

Or 91mm wide and 910mm long?
If so, you shouldn't install them floating anyway - you will create too many 'hinges'.
Glueing down would be an alternative.

Please do confirm the width and the lengths of your boards.

 

[al4567]

They are 910mmm long, by 122mm wide, 18mm thick Acacia.

We want them to run across the house, the same direction as the original floorboards, hence being floated over hardboard and underlay.

 

[WoodYouLike]

122 mm is wide enough to install floating, although I would be a bit reluctant in floating 910mm long boards. Make sure you don't end up with a fixed pattern in your floor, do try to stagger randomly so that joints are randomly located to give your floor more stability

 

[al4567]

I was thinking to stagger them at 1/3 board intervals, but that would create a shallow diagonal line of ends. Is that acceptable or should it be more random?

 

[WoodYouLike]

More random, especially when the length of your room is the same everywhere.

 

[mattysupra]

what do the instructions say about install? Do they say floating using pva? or do they say to glue or nail to subfloor, hence the tongue area being sealed?

 

[al4567]

Not seen any instructions yet! Just lots of sealed boxes......

The test piece I glued(unsanded) yesterday seems to have an excellent bond! I will test it destructively this evening though(it's only 6" long), to see whether there is any true bond or not.

 

[al4567]

Just a note.... I destructively tested the glue joint today, and when it failed it showed exactly what I suspected, that the glue seperated cleanly from the surface of the lacquer, leaving the Lacquer behind.

However! It took most of my weight on a 5 inch length of tongue and groove joint to separate it! I propped one side of the piece up an inch, and stepped on the middle, a pretty severe test!

The very ends where the board was sawn, had bonded properly, and had left wood behind when the rest separated.

So I'm pretty happy with the idea of a very quick pass with some 60 grit over the tongue and groove portions before bonding. Although there are a lot of boards, it shouldn't cost more than a few seconds per board.