Plywood v OSB

[Slinger]

Morning All,
A couple of questions from a newbie, who has recently retired. My last 'proper woodworking' was in my last year at school (1952) & I have a lot to catch up on! I wish to build a bench as per http://www.finewoodworking.com/FWNPDFfree/011181054.pdf which was mentioned on this site some time ago. My skills are very limited (outside of a 7lb hammer & 6" nails), but this bench looks to be a good starting point for me. It seems to be made purely out of plywood & my questions are;

1. Particularly in the legs, stretchers & rails, can I use (because it will be cheaper), OSB in the inner layers instead of plywood, which will only be used on the outer layers & can I glue plywood to OSB & OSB to OSB, or is there a problem with the OSB delaminating as a result of the glueing?
2. If I can, what is the best glue for purpose?

Thanks for your help.

Slinger

 

[twothumbs]

OSB has a wax coating to give it a waterproofing during installation. It is good stuff though. How about screwing it at say 6" centres and putting your ply top, on top. Making up legs by several layers is a good way of overcoming all the jouinting and so on.....when you haven't got a bench. Perhaps you could use redwood in layers to make up the legs and stretcher thickness required. Glued togerther as the plans with pva. and clamped or weighted down. Alternatively, you could glue and screw the pieces together and save on clamps. Remember you are making a bench to use and that doesn't happen until it is made, so do not be too distracted by too many niceties. I made metal working bench 20 years ago with 2 layers OSB and hardboard top and still good. I have, against all 'good' advice' made big set squares and other things by building up glued layers and have always got good tight joints. If you have concerns about the bench shaking or tightness of joints ...screwed rod (say 10mmm dia) is good at pulling up jonts super tight. Best wishes and as they say enjoy.

If interested in the rod idea I can elaborate.

 

[twothumbs]

Press keys too many times.

 

[johnwc812]

Hi Slinger
Know nothing re OSB. The bench design very clever, just 2 concerns: When the bench top gets a bit worn can it be refurbished, resurfaced, planed or whatever?
Bench joints work loose relatively quickly, especially if a lot of hand planing is done. A ply (or OSB) panel screwed to the back may be worth considering.
Good luck with this project.
John

 

[Eric The Viking]

I wouldn't use OSB: it has little structural strength, isn't very dense, and isn't waterproof long-term either. It also produces nasty splinters, occasionally has metal fragments in it (don't ask me how I know!), and won't glue well, no matter what you do with it (it's not well glued together to start with!).

You might use two grades of ply instead, possibly. It'll be denser, stronger and will finish better too, if you use a good sharp saw to cut it with.

Just my twopence.

E.

PS: forgot to add: my bench is made of Canadian redwood of some sort, spruce I think, with a chipboard top faced with ply. Following from Twothumbs' comments: mine is also pulled together with bolts (although the end frames have big M+T joints), and the end result has never worked loose, although it gets pulled and hammered in all directions a lot, obviously.

 

[Slinger]

Thank you to everyone who has replied, the points made are very helpful, it is very much appreciated. When I can get my brain round it, I will make a start.
Slinger