Can I build a workbench from tanalised pine?

[Adam Sisson]

I have 2 options to get material for my new workbench:
1. get the timber delivered from Wickes for £78
2. get the timber from my local timber yard for £76 - but it's tanalised stock.
My question is, will the tanalised stuff be too wet, and warp as it dries? I plan to run it all through the thicknesser once I get it so the edges are true. I'm keen to support the local business, but I need the wood to be suitable for the job.
Another secondary question, is 75mmx75mm a big enough cross section for the workbench legs? it's mostly for hand tool work so likely may be taking a beating (mallets, chisels, etc.)
attached a picture of my design.

 

[beech1948]

The first thing to do is to look up the list of chemicals used to impregnate the timber then research the likely effects on humans of prolonged contact. That should be enough to put you off using treated timber.

Second reason is that untreated timber should be slightly cheaper. Dryer and less likely to distort due to drying strains. Go to a timber yard and pick from their pile.

Undercarriage of 75x75 will be a bit spindly and you would do better to use 100x100 or even better 150x150 for a heavy solid base.

 

[Peterm1000]

Go to a timber yard and pick from their pile.

Best advice... You can do that at Wickes or Homebase too. There is a massive difference between the various CLS you can buy there. Some is total scrap and some virtually knot free.

 

[Bodgers]

I have 2 options to get material for my new workbench:
1. get the timber delivered from Wickes for £78
2. get the timber from my local timber yard for £76 - but it's tanalised stock.
My question is, will the tanalised stuff be too wet, and warp as it dries? I plan to run it all through the thicknesser once I get it so the edges are true. I'm keen to support the local business, but I need the wood to be suitable for the job.
Another secondary question, is 75mmx75mm a big enough cross section for the workbench legs? it's mostly for hand tool work so likely may be taking a beating (mallets, chisels, etc.)
attached a picture of my design.

Why is your local timber yard only selling tanalised pine? That seems a bit...bizarre.

I'm going to hazard a guess and say it is because you are asking for 75x75 material. Which mean that's stock designated for fence posts.

So basically we are talking about sawing and chiselling away at tanalised fence posts... toxicity questions aside, the kind of stock you will be dealing with means it is not going to be a pleasant experience. It is the lowest of the low quality.

My advise would be to get standard pine, of less chunky stock and laminate up. SPR stock, stored under cover, will even be of better quality. Select it in person.

Paul Sellers has some good videos on making a bench using this technique, check them out.

 

[Trainee neophyte]

Many years of working with treated timber has taught me two things: firstly, it is for agricultural quality workmanship - do you want a farmer's workbench? It will arrive fresh from the treatment tank, and be saturated, and then go banana-shaped as it dries. OK for a sheep shed, but for a shiny work bench?

Secondly, nasty septic splinters - i don't know if it is the quality of the wood or the treatment process, but there always seem to be inch-long lumps of wood sticking out of your hands when you work with it, and they always make for evil, puss-filled wounds. I would NOT want a pressure-treated bench, personally.

The good news is that I don't believe that they are allowed to use arsenic in the process any more, but I may be wrong. https://en.m.wikipedia.org/wiki/Wood_preservation

 

[Deadeye]

Well, a small counterpoint to the comments above.

I've built a couple of storage trolleys from treated C24 timber, including drawers. This was mostly on cost grounds but also accessibility to me - I have a nearby construction yard for that sort of thing but it's a fair old trek to get anything different. I also don't have a long car anymore! Originally I did it because that nice Mr Wandel seems to get good results with "construction lumber".
I get 6x2" and resaw them on the table saw (150mm from each side) to make the drawer parts. Once planed they're fine as long as I use them quickly... otherwise they do tend to cup.
I plane down 4x2" for the frames.

Not had a problem with splinters, but I guess glovers would help. As for the chemicals, well, the usual dust extraction handles the build issue. I'd argue long term exposure is less of a concern - after all my shed is already made out of treated timber and I spend a long time in that!

Final point - pick your own and get straight, heavy and clean. There are some awful pieces but also some surprisingly excellent ones. If you take light pieces they can be very soft (I put 18mm ply on as a top layer on my wheeled chests of drawers). No, they won't be mansion house fine furniture, but sanded and three coats of varnish and they're very durable and not unattractive.

Each to their own though.

 

[Deadeye]

I meant 75mm from each side!

 

[Bodgers]

Well, a small counterpoint to the comments above.

I've built a couple of storage trolleys from treated C24 timber, including drawers. This was mostly on cost grounds but also accessibility to me - I have a nearby construction yard for that sort of thing but it's a fair old trek to get anything different. I also don't have a long car anymore! Originally I did it because that nice Mr Wandel seems to get good results with "construction lumber".
I get 6x2" and resaw them on the table saw (150mm from each side) to make the drawer parts. Once planed they're fine as long as I use them quickly... otherwise they do tend to cup.
I plane down 4x2" for the frames.

Not had a problem with splinters, but I guess glovers would help. As for the chemicals, well, the usual dust extraction handles the build issue. I'd argue long term exposure is less of a concern - after all my shed is already made out of treated timber and I spend a long time in that!

Final point - pick your own and get straight, heavy and clean. There are some awful pieces but also some surprisingly excellent ones. If you take light pieces they can be very soft (I put 18mm ply on as a top layer on my wheeled chests of drawers). No, they won't be mansion house fine furniture, but sanded and three coats of varnish and they're very durable and not unattractive.

Each to their own though.

C24 construction/carcassing timber is a different thing to tanalised external timber - such as 75mmx75mm fence post material. The stuff that Mattias is using in his simple workbench (for example) is definitely not tanalised.

I have made a timber rack and a XCarve station from SPF C24 and it was fine. A bit knotty but good enough for a first bench.

C24 is typically used in wall studs and internal house structures.

75x75 tanalised is going to be fairly unpleasant to be running through a thickness planer and working with hand tools in a small workshop...

 

[Phil Pascoe]

Don't forget it's very easy to save yourself £20 on materials and buy yourself a morning's hard work by doing so. Damhikt.

 

[Osvaldd]

I have some 75x75 timber I’m going to make a bench top from. None are treated though, at least I don't think so. It is my understanding that the treated ones have this green-ish, sometimes yellow-ish colour even after planing the surface, which tells you that the chemicals were absorbed deeply into the wood.

 

[novocaine]

C16 CLS 63x38 from B&Q is 2.70 a stick. legs and top can be laminated although I'd possible go up to 89x38 if I did it again as you'll lose 3mm minimum planing the top (although it's proven to be thick enough for me). I think I did the first 4 and last 3 at 63mm then turned the inner 3-4 side on so thay are 38mm thick. 10 sticks for the top.
legs were laminted as said, used 4 sticks there.
another 6 for rails and styles. today of 20 sticks, grand today of 55 quid although I think I paid less as it was on bulk purchase discount.

don't use treated, it's horrid.

 

[AJB Temple]

By far the best advice I can give you, is make the legs big and thick and the whole structure as rigid as possible. Flimsy benches are annoying when clouting chisels with a mallet.

 

[thetyreman]

look for redwood/scots pine and use that instead, it's far nicer on your tools, also try and avoid spruce, the knots are like concrete! one swipe with a razor sharp plane it's blunt in an instant if you aren't careful, the chemicals in treated/tanalised timber are designed for things like fencing outdoor gates e.t.c or flower beds, it just wouldn't be right for a workbench and potentially not good for you long-term.

 

[thetyreman]

also you could improve the design by using through mortise and tenons instead of lap joints