Can i joining scaffold board edges with pocket hole screws?

[TomP]

Hi,

I'm going to be making a top for a counter, the top has to be three meters long, however i only have four long clamps long enough to co across the width of them glues up.


I was wondering could i use pocket hole screws to pull the edges together or would this pull the board to the side the screws on so its not flat anymore?

Tom

 

[Wildman]

don't worry about clamps make your own and use wedges

 

[novocaine]

Dont worry about it not being flat. After a week inside it won't be flat anymore.

Wildmans suggestion to make wedge clamps is a good idea.

 

[Estoril-5]

Excuse my ignorance but how do you make your own clamps and I'm assuming a wedge is not a potato based food product?

Sent from my Moto G (4) using Tapatalk

 

[novocaine]

length of wood long enough to reach across your work piece. screw a piece of wood at one end (with a nice flat side), put it across your work and screw another about 2" from the other side.
use 2 wedges in the gap between the edge of your work and the block, knock them in with a hammer.

heres a nice picture of a posh version with holes in, same principal, I prefer a flat and 2 wedges though.

(source, http://www.tdpri.com/threads/wedge-clamp.278483/)

 

[marcros]

these are even easier to make, and work well http://theapprenticeandthejourneyman.co ... el-clamps/

 

[novocaine]

they are.

I found I could get more force from a wedge style, but you shouldn't need a lot of force if you jointed the boards correctly.

so now you've got choices.

 

[pike]

Tom, the boards would probably move as you screwed the pocket hole screws in. You're supposed to have the faces clamped to keep them flush while you drive (which is obviously not easy in the middle of a table top). You might be able to use cawls?

Or diy clamps as suggested by others. I find sash clamp heads are handy to have around for making additional long clamps.

 

[marcros]

Or...

Pinch dogs?

http://www.theenglishwoodworker.com/pin ... nts-clamp/

I used these on a table top to good effect. I had forgotten all about them though!

 

[TomP]

without going overkill what would a reasonable amount of clamps be for the length of a thee meter surface?
?

 

[novocaine]

1 a foot. you've heard the adage that you can never have to many clamps? this is the reason why.
honestly though, assuming you've got perfectly jointed boards, you can get away with 6.

you aren't gluing them all up in 1 go are you? best bet is to joint them in pairs then joint the pairs in pairs. lets you get away with shorter clamps for some of the glue up and you can use weights on top (the other boards) to hold them flat instead of clamping from both sides.

 

[Nelsun]

If you have access to an MFT type work surface of sufficient size you can use 4x2s (or whatever is to hand) laid across the boards and clamped down through the dog holes to help keep things flat. Just take precautions not to glue your boards to the worksurface (hammer)

 

[dzj]

You could use miter bolts for countertops.

 

[flying haggis]

biscuits??

 

[Cordy]

Dominos and your existing clamps ? :roll: