Beginner advice on birch plywood

[capocobono]

I've decided to create some office furniture from hardwood birch plywood. I've always liked the look of the layered ends and thought it would be perfect to use in a home office space. I have found out however that it is quite expensive and only comes in 2440x1220mm sheets. I have done a fair amount of research on how to manage the sheet size and I've planned the cuts as efficiently as possible, but I'm new to working with plywood or anything as big as this, so I thought it would be worth gaining some insight from anyone who's worked with this material before. The thickness I'll be working with is 18mm. These are long grain sheets of Russian Hardwood birch plywood. It's really nice stuff and I'm terrified to mess it up.

My first question is, what's the best way to cut large sheets like this but keep tear-out to a minimum. I was planning to use my circular saw to chop the pieces down into manageable chunks. The idea is to lie the sheet down on the floor with some scrap 2x4s underneath as support. I've seen some good tutorials on how to make a guide rail to keep the edges straight. Then I would use finer saw blades to cut the pieces that I need for the cabinets. Unfortunately I don't have a table saw, nor could I afford one close to the specs needed for such a task. The most challenging pieces will be the 2m high bookcase ends, but I'll be ripping with the grain on those, so I hope that's easier. I have three different saw types: The general purpose 24 tooth dewalt blade (for roughly chopping down the sheet), a finer 40 tooth blade (which I would use for ripping with the grain) and a 100 tooth fine saw blade (for cross cutting). I've heard that tape doesn't really help, but that seems to be contentious.

The second question I have is about joining pieces. Let's say for example the bookcase shelves. The design is basically two simple boxes of 18mm ply one on top of another, then a larger box of ply around the whole thing, so it ends up double thick. For the inner boxes, since everything will be hidden, I was thinking of the simplest method of using counter-sink and pilot holes, then screws straight through the face of the support and into the end of the shelf. Or I was going to use underside pocket holes for those then dowel fill the holes; this might be stronger given the nature of the overlapping structure of the ply? Either way would be supported by glue. I want to avoid making any tongue and groove joints or lap joints because I don't really have the correct tools and I don't really like the look of joints on exposed plywood ends. Simple butt joints are my preference. Interested to hear your thoughts.

The last question I have is on finishing. I'm keen to stain the exposed layered ply edges a darker colour than the light birch face so there's a nice contrast. Then I would like to coat the whole thing with something that keeps the wood looking natural, but is practical for an office space. For the desk surfaces I was thinking of a hard wearing clear epoxy, but I've never used that before. I definitely don't want to use paint or stain on the faces. I wonder if any of you have used some nice natural looking but hard wearing finishes on birch before.

I've attached a rough plan of the bookcase. The bottom inner box will have doors, which is why it's slightly inset.

Please tell me if you think anything I'm doing is wrong or if you have any suggestions on how I can make sure I don't ruin some lovely material.

 

[AJB Temple]

Circular saw is doable if the blade is very sharp and not too coarse. However, it would not be my tool of choice: I use a tracksaw. Mine is a Mafell and I get very little breakout (none in fact). Tracksaw is great as you get super precise accuracy and excellent finish. It is also very quick to set up. You can get much cheaper ones but I have never tried one of those. (Festool good - quite often seen second hand, but also not cheap).

You really need a bench the same size as the sheets you are cutting. This can be done with thick flat board and a thinner sacrificial top sheet, on some sturdy trestles. You will need to brace it all up underneath with some 4 by 2s or similar, or you will get sag in the centre. This will affect the accuracy of your ply cuts.

Be aware that 18mm ply is nowhere near as rigid as 24mm ply.

 

[Yojevol]

This is an ambitious project requiring a lot of accurate sawing. I would seriously think about getting the board supplier to cut the parts to your cutting list.
Concerning joints, I think your use of screws is perfectly viable but I suggest that all shelves are full width so that you are not reliant on the screws taking the vertical loads.
Are you thinking of a backing sheet to stabilise the whole structure?
I wouldn't like to comment on finishing at this stage.
Brian

 

[AJB Temple]

To add to my earlier post, if you get a good tracksaw, not only will the track prevent top break out, but very accurate depth setting and a sacrificial layer below also stops bottom break out. You can also use the scribe functions.

I use lots of baltic birth ply and it is worth being aware that the faces can create very sharp splinters. Get some gloves.

Also most board in the UK now at the upper end, unless you are paying extreme premium, is B/BB. The BB side can be patched. So be very clear about your cut planning and which will be the face side.

 

[Doug71]

As recommended get a track saw, even the cheap ones are okay (or so I'm told)!

Then get one of these and some dogs to keep your cuts square, a bit of googling will show you how to use it.

https://www.cncdesign.co.uk/replacement ... p-top.html

It's a bit of an initial outlay but will make things so much easier.

 

[capocobono]

Thanks for the advice. I wish I had a tracksaw, but budget won't allow. I also don't have any trestles, just a small bench. I figured the garage floor on some 2x4s would be suitable. It's pretty flat and I don't mind cutting from above. I am worried about it bowing upwards in the middle though since the sheets are so big. Maybe something heavy on there would stop that?

I've seen the 18mm plywood and probably wouldn't use it for something so big. That's why in this case I'm doubling up the boxes and putting loads of supports on the shelves.

Interested to know what's your view on straight through screws vs pocket holes?

 

[capocobono]

This is an ambitious project requiring a lot of accurate sawing. I would seriously think about getting the board supplier to cut the parts to your cutting list.
Concerning joints, I think your use of screws is perfectly viable but I suggest that all shelves are full width so that you are not reliant on the screws taking the vertical loads.
Are you thinking of a backing sheet to stabilise the whole structure?
I wouldn't like to comment on finishing at this stage.
Brian

I have a prepared clear cutter guide for myself. It would definitely be worth asking if the timberyard would be able to make the cuts. Especially if I made all the shelves full width, that would be many more cuts to get absolutely spot-on. There won't be a backing sheet as this is a room divider. I'll be securing it to the wall on the right elevation, possibly even the floor as well.

 

[AJB Temple]

I suspect, based on your second post, that your laudable ambition may outweigh your ability. Trying to get really clean furniture quality cuts in expensive (if it is proper birch ply) on the floor with a circular saw is going to be a real challenge. If the base of the ply is unsupported you risk a right mess on the break out side.

Trestles are easy to make / cheap to buy. So is a sacrificial board (cheap).

You came here to ask for advice. Your method is not great for a good finish. Don't waste good materials with poor method. No offence intended, but there is a learning curve and part of the point of this forum is to ask experienced people how to avoid expensive mistakes.

 

[capocobono]

I suspect, based on your second post, that your laudable ambition may outweigh your ability. Trying to get really clean furniture quality cuts in expensive (if it is proper birch ply) on the floor with a circular saw is going to be a real challenge. If the base of the ply is unsupported you risk a right mess on the break out side.

Trestles are easy to make / cheap to buy. So is a sacrificial board (cheap).

You came here to ask for advice. Your method is not great for a good finish. Don't waste good materials with poor method. No offence intended, but there is a learning curve and part of the point of this forum is to ask experienced people how to avoid expensive mistakes.

Oh, you've got me wrong. The whole reason I'm here is to ask advice. I'm absolutely going to do what you said if you think the floor rig is flawed. What weight of sacrifical board would you suggest?

 

[AJB Temple]

What you want on your trestles is anything thick (so it will not deform) and flat. So cheap thick ply, blockboard, OSB. My present sacrificial board is a sheet of 9mm MDF, that was damaged and sold by Wickes for 50 pence. That goes on top of the support board. You cut into it by about a mm.

I know people are iffy about MDF, but as I said I am using a tracksaw, and it is hooked up to a powerful extractor. You will be fine with a cheap tracksaw and a cheap (eg Lidl) extractor (wet and dry vac - about £50). Your extractor is best with a power take off. Clean cuts are greatly improved by removing the dust at source.

 

[Richard_C]

Our local supplier will cut sheets of 8x4 on the spot, you select the sheet from the rack. If I recall they do 2 cuts free and something like 50p per cut after that presumably to stop people expecting then to do detail. Its well worth it if like me you don't have the proper kit to do it yourself.

I normally pre-plan and have them do some cuts, much cleaner and more accurate than I can manage plus I'm not humping big heavy boards around in a small space. Suppose for instance I want a lot of 300mm wide components, bit like your design maybe, I'll have them cut 3 x 300mm full length strips and do the cross cuts myself at home by hand or with a circular saw.

*It's obvious but don't forget to plan for the width of the saw blade, if you take 3x300 from a 1200 sheet you won't have 300 left - you will have 3 blade thicknesses less than that so maybe 292.

Is there anyone near you who can do that?

 

[Keithgrif]

Some people advocate a big sheet of insulation foam as a sacrificial underboard, then working on the floor could work for you perhaps

I'd recommend buying some cheap ply first just to practice, a piece of 4ftx2ft will only cost you £15 or so.

 

[Stanleymonkey]

Your design looks really well thought out.

If I can make a suggestion - get hold of an offcut of ply (scraps bins at big store / offcut pile by the woodcutter at B&Q / skips are my favourite supply!!)

Make a medium sized box using your chosen method. Try out some fixing techniques while you are at it. Try and make it for something useful like a storage box for tools or a couple of knee high boxes to support items your are sawing. Even if you have problems you might make something that makes life easier on the next attempt. : )

I don't remember clamps being mentioned. How are you planning on clamping up? It's an important part of it. Clamping up a large item can be hard work.

Good luck with it - definitely agree with getting the supplier to cut it to width for you. You'll get 200 -> 300mm wide boards into most cars. A full size board is an utter nightmare unless you have a van.

 

[capocobono]

Thank you everbody for the advice. I know that this is an ambitious build and I'm not taking it lightly. The good thing is I have all the time in the world to get it right, so I'll be making plenty of smaller practise cuts and joints before I tackle the main boards.

I've asked if the timbermill will make some prelimenary rough cuts just to get the boards down to more manageable sizes, that was a great idea as the cuts aren't expensive. I've also ordered extra 2x4s to build my own raised platforms so that I'm not scrambling on the floor. I've also asked the supplier to add some larger damaged sacrificial boards, which they offered for no extra charge.

One thing I forgot to mention is that I have a Kreg Accu-Cut system for my circular saw which I'm hoping will help with the precision and tearout. If after all that I'm not satisfied with the test cuts, I'll have to convince the wife to let me buy a tracksaw.

P.S. Somebody mentioned clamps. I have clamps coming out my ears, quick release clamps, C-clamps, corner clamps; everything gets clamped, then clamped again!

Thanks again.

 

[TheTiddles]

Without a back-board I think your design is going to rack a lot, if you attach the entire side to the wall that should do it, just remember the wall is unlucky to be straight or perpendicular to the floor, which won’t be flat either so some form of stand to compensate will be a good plan, it will also stop it being kicked into.

Rustins satin finish interior varnish works well on ply, fast to apply, a good tough finish that doesn’t make it turn wee yellow or look glossy and brash. Finish before assembly, it’ll be way easier to roller on the flat. Mask where you need to glue.

Getting all the ply cut by your timber merchant will cost you, possibly £10... given that their blades are usually properly maintained on good and very accurate machines, I’d go down that route, save you the agony of a bad finish you can’t do anything about and let’s you focus on making, not cutting. SketchCut lite is free and great for layouts one an iPhone.

Glue and screws will be fine if done right, I’d suggest you make a couple of jigs for laying out and drilling to speed it up an think carefully, you can probably hide most of them, plugs of sycamore or birch can be used on visible faces.

Aidan

 

[Jamesc]

Having made a number of cabinets recently for my son in birch ply I have a few comments on things I learned along the way.
I have a tracksaw and good table saw set up but if available would defiantely use a panel cutting service. 18mm ply is really quite difficult to handle on your own.

Give yourself plenty of allowance for saw cuts, also remember the edges may have defects from strapping down or handling so plan to lose the first 10-15mm at least.

When finishing I found a nice sharp block plane followed by sanding using a long backing block on the edges (an offcut of ply) worked best.

I sanded the edges down to 400 grit - probably a bit excessive but it helped to make the laminations pop which was my brief.

Under no circumstances be tempted to use a power sander on the edges, you will round them over and it spoils the look.

I used Danish oil as a finish as it is very straightforward to use. I applied in very thin coats wiped on with a rag and denibbed with 400 grit between each coat. Danish oil gives a golden colour which may or may not be what you are looking for.

Use an extra few coats of finish (I did 10 - 12 very thin coats) on the edges as they are more absorbent than the faces.

 

[capocobono]

Without a back-board I think your design is going to rack a lot, if you attach the entire side to the wall that should do it, just remember the wall is unlucky to be straight or perpendicular to the floor, which won’t be flat either so some form of stand to compensate will be a good plan, it will also stop it being kicked into.

Rustins satin finish interior varnish works well on ply, fast to apply, a good tough finish that doesn’t make it turn wee yellow or look glossy and brash. Finish before assembly, it’ll be way easier to roller on the flat. Mask where you need to glue.

Getting all the ply cut by your timber merchant will cost you, possibly £10... given that their blades are usually properly maintained on good and very accurate machines, I’d go down that route, save you the agony of a bad finish you can’t do anything about and let’s you focus on making, not cutting. SketchCut lite is free and great for layouts one an iPhone.

Glue and screws will be fine if done right, I’d suggest you make a couple of jigs for laying out and drilling to speed it up an think carefully, you can probably hide most of them, plugs of sycamore or birch can be used on visible faces.

Aidan

Great idea to use a jig for the drill holes. A lot of the reason for doing this job is so that I learn how to cut sheet material properly. I was thinking of asking them to cut anything over 1.2m and allow me to cut the rest. I'll know for sure what I'm comfortable with after I've made my test cuts.

I'm leaning towards a mix of 60mm wood screws and dowels for the majority of the inner boxes. Possibly 80mm screws for the bottom shelves since they aren't as well supported. Just need to be very careful with the straight angle. Not sure yet how I'm going to hide the fastenings on the outer box (mainly just that outer left face). Since it's quite a lot of surface area for the glue, I might get away with hidden head pins. Can you think of a better solution for that?

Thanks for the advice on the finish. I'll give that a look.

 

[robgul]

If you're going for top quality Birch ply then get it cut to your sizes professionally - unless you have top quality tools (and ability!!)

I've just built a rather special piece of furniture in 18mm ply with exposed edges, some doubled up to 36mm for a really solid effect.

I bought the board from a firm call Cutlist (near High Wycombe) https://cutlist.co.uk/ - they cut everything to precise measurements from my cutlist - really sharp edges with no breakout whatsoever.

Depending how much you need the material wasn't much more than the local timber merchant, there was a cost for cutting but that was offset by the risks outlined with self cutting (and I have a tracksaw!) They deliver, for a price, but I was going that way so collected the cut boards.

 

[Racers]

+1,000.000 on a cutting service I wouldn’t dream of making something like that without using one. As it’s going to be seen on both faces you have no where to hide any mistakes.
I needed something like that so I bought an Ikea Expidit.

Pete

 

[Hornbeam]

Looking at your sketch there are a number of issues. You need to think about how you will get a perfect fit of 1 box within another as even a very slight gap will show.
18mm ply is quite thick to be cutting with a hand held circular but can be done using a guide batten and a good quality blade. Cann be done on battens on the floor but much easier on trestles
Your sketch gives no indication of the joints. Are the shelves movable?.
The less joints the more prone to racking so can you incorporate some stiffeners. Do all openings have to be totally open?
Ian