worktop made from boards.. best joining method?

[kaseryn]

I made a shelf/worktop from 3 long lengths of 9x1, only screwed through batons underneath into the planks, its a weak grip and warp has opened them up. Idea's for tightening it all up better? I could screw through from the top and get a much better bite into the batons.. or i was thinking maybe bolt through and get a really tight grip to stop the spreading.. is it too thin to use cams or some sort of fitting to lock it all together? Just looking for a few idea's

cheers!

 

[foxhole]

Should have been clamped and glued and biscuit jointed as well a screwed , you will struggle to remove warp once it has formed.

 

[Burnerman]

Good morning!
As you've effectively made a shelf / top measuring 27" x 1" expect warping big time, so keep those battens beneath.
I reckon the best way to join these planks it to use a biscuit jointer, biscuits and PVA glue, held together for a while using about 4 sash cramps until the glue has set.
Cheers John

 

[kaseryn]

I'm pretty confident of removing the warp with clamps, but i don't have a biscuit jointer. The glue will help though..

 

[big-all]

to do it properly you need to rip them down the middle alternate the growth rings up then down then up
glue and dowel or buiscut joint and clamp then you wont need battons underneath

 

[kaseryn]

That's an interesting point about the growth rings.. but surely you wouldn't always do that with full planks would u? I can see the sense of it warpwise though. As i don't have the jointer i'll probably go with the bolt method or screw through plank and baton/glue.. the holes are already there anyway. For future reference :


~ recommend.. makita 3901 or dewalt dw682k in the £200 range.... or another?

~ at what sort of intervals would you need to have the joints in eg these 9x1's?

~ is dowel drilling done manually.. or are there guides of some sort to keep everything aligned/centered/matching?



Thanks!

 

[big-all]

yep standard industry practice if stability off large widths is required

 

[kaseryn]

Ok.. so what do you think of the Makita jointer? How far apart should biscuit joins be? And whats the craic with dowel jointing? is there a machine for it.. guides.. or all manual?

cheers!

 

[big-all]

cut a contiuous slot stopping 20mm short off each end and alternate a buscuit then a space for heavy use medium use 1 to 4 spaces light use every foot

you can use a router cutter for this purpose
http://www.toolstation.com/shop/Pow...scuit+Jointer+Router+Bit+14/d80/sd2579/p69882

dowels in general every 8 to 14 inches buy 3 packs off 4 dowel points as you will need 8 for a long board and they are often mislaid

basicly you drill the holes on one board pop the points in the holes
line up the board with its neibour the pins will mark the hole centres

dont pay much more than 1p per 8x30 dowel certainly no more than £12.50 1000 3 packs off dowel point about £5

 

[kaseryn]

Ok thanks for that.. it sounds like it'd be too easy to get a less than flush finish with the dowels. I'm gonna need to get a router and i suppose table.. can you recommend a good medium priced setup 110v?

 

[big-all]

you use a £12 jig that lines up all the holes from the top face and where the points holes are you highlight with a pencil
place the hole jig over the hole with the black dot central and the jig will give you the correct height for the hole

routers dewalt trend hitachi makita dewalt and trend are very compatable and interchangable add ons and jigs and bushes

if you have a table saw with a movable gaurd and riving knife you can on 2 passes or more cut a 4 or 6mm groove 13mm deep to accept a bit off ply 24mm wide
just work from the same face and make shure edge on the table is tight to the fence

 

[kaseryn]

Ok, cheers!

 

[big-all]

read the tablesaw addition

 

[kaseryn]

When you described a continuous groove for the biscuits, i did think of simply splicing with a rip of some kind.. would seem strong and less hassle than individually doing all the biscuits.. i don't have a table saw but a routed trench would make enough room for what.. 4mm... 5mm rip?

My concern with all of these is how effective they'll be preventing the boards spreading/warping laterally. I know they'll flush this way, but the spreading has been the bigger problem.. without something locking vertically, i wonder.

 

[big-all]

i assume you will have a basic frame underneath!!!!

the reason you have spaces is because the wood expands and shrinks between 3 and 6% across its width and virtualy nill along its length

so your battons remain at 28" where as the board are loosing around 5mm each

as long as you use slotted screw holes or brackets there will be no expansion or contraction forces and the framework will hel hold any warp or twist movements in check that will be 1/4 what they where before as the cupping motion on one bit cancels out the next