9mm birch ply box...need advice..help

Sean Farrell · 24-06-2021 9:58am #1

what would be the best way to join the sides of this 9mm thin plywood box ?. dont want finger joints or dovetails ....straight gluing wouldnt be strong enuf.....I tried gluing and small screws then plugged them...not a great result.
I thought of 6mm dowels...even searched online for makitas mini biscuit jointer...no luck either. Any suggestions would be really appreciated.

Odelay · 24-06-2021 10:00am

Sean Farrell wrote: »

what would be the best way to join the sides of this 9mm thin plywood box ?. dont want finger joints or dovetails ....straight gluing wouldnt be strong enuf.....I tried gluing and small screws then plugged them...not a great result.
I thought of 6mm dowels...even searched online for makitas mini biscuit jointer...no luck either. Any suggestions would be really appreciated.

Can you put in a corner fillet piece?

Sean Farrell · 24-06-2021 11:36am

Odelay wrote: »

Can you put in a corner fillet piece?

Like this...is this what you mean?

fiacha · 24-06-2021 11:55am

Splined mitre joints for the sides and rebates to join the top / bottom pieces ? Add some small pins which can be punched and filled.

Odelay · 24-06-2021 1:14pm

Sean Farrell wrote: »

Like this...is this what you mean?

Yes. Glued and screwed from the inside.

Sean Farrell · 24-06-2021 1:17pm

QUOTE=fiacha;117501240]Splined mitre joints for the sides and rebates to join the top / bottom pieces ? Add some small pins which can be punched and filled.[/QUOTE]

Rebates for the lid is a great idea...nice one. The mitre joints wont work for what i'm doing...but the panel pins with wood glue might be strong enuf.
I use 00 biscuits on 12mm stock..works well on joining the sides...but it cant go any lower..
You can see the screws are not aethestically pleasing here. I could countersink and plug....but screws rust! small hardwood 6mm dowels could do it.

Anybody know of the legendary mini biscuit jointer that can do 0000 biscuits. If not i could buy a 6mm dowel jointer ...planning on making a few!

Sean Farrell · 24-06-2021 4:52pm

Thanks Odelay..its an option..but i find that way kinda not quite what i'm looking for.
Here's the rub...i put an image on the sanded ply sides...then in panel form each side of the box is varnished multiple times and then coated with a wax finish. It gives plenty of protection.

But because its done this way...some joinery techniques are'nt suitable when assembling the box.

The only way i can think of doing a proper look the box is either screws hidden by plugs, or small dowels or as i said very small biscuits.
Still is there another way I wonder?

Calahonda52 · 24-06-2021 5:06pm

You really should remove the images with the child identified

tabby aspreme · 24-06-2021 10:34pm

Route a groove for a loose tongue on the faces you are joining, and glue it together, you would need a 3 or 4 mm bit for this though.

recipio · 25-06-2021 10:41am

There are all kinds of options but it comes down to the equipment you have. Glueing dowels into butt joints is probably the easiest and looks OK when sanded down.( Baltic Ply has a thicker outer veneer and will take a little sanding )
I'd second the above thread suggesting a spline let into a groove in the endgrain/ face of both pieces. It can be done on a table saw but the trick is have a scrap of ply that is snug fit in the groove.
I'd avoid Mitres as I suspect they are a bit beyond your experience.

the_pen_turner · 25-06-2021 11:13am

PU glue and brad nails will be very strong.
a corner piece on the inside would add a crazy amount of strength as well.

recipio · 25-06-2021 1:10pm

the_pen_turner wrote: »

PU glue and brad nails will be very strong.
a corner piece on the inside would add a crazy amount of strength as well.

With respect, both would look amateurish .If using brads its worth milling a rebate in one piece to a depth of 7 mm leaving a small 2mm thick endgrain exposed. It will add a bit of strength as well. This assumes the OP has a few suitable clamps to hold it all together.

chillyspoon · 25-06-2021 1:11pm

I've used 3mm bamboo dowels (aka bbq skewers!) with great success in loads of narrow thickness joinery, their fibrous nature makes them seriously strong in the direction of orientation.

the_pen_turner · 25-06-2021 2:38pm

recipio wrote: »

With respect, both would look amateurish .If using brads its worth milling a rebate in one piece to a depth of 7 mm leaving a small 2mm thick endgrain exposed. It will add a bit of strength as well. This assumes the OP has a few suitable clamps to hold it all together.

You wouldn't even see the pins if done properly. 23g pins would be almost invisible.
Not sure such a severe rebate would any significant strength.
It doesn't seem like the inside is very important but a small corner piece that is a triangle wouldn look decent enough.
The strength of pu adhesive is amazing. I have roughly tested it and it shocked me. In some cases holding my body weight

recipio · 25-06-2021 3:17pm

the_pen_turner wrote: »

You wouldn't even see the pins if done properly. 23g pins would be almost invisible.
Not sure such a severe rebate would any significant strength.
It doesn't seem like the inside is very important but a small corner piece that is a triangle wouldn look decent enough.
The strength of pu adhesive is amazing. I have roughly tested it and it shocked me. In some cases holding my body weight

I think you are assuming the OP has a nail gun ! The point of the rebate is that it looks better and you can drive brads 'from the side' like a drawer. PU is good but a bit messy and I gave up on it as the container usually hardened before I could use it all.The real strength of small boxes like this comes from glueing in a plywood base into a rebate at the bottom and 9 mm will allow plenty of depth for that.

the_pen_turner · 25-06-2021 3:43pm

recipio wrote: »

I think you are assuming the OP has a nail gun ! The point of the rebate is that it looks better and you can drive brads 'from the side' like a drawer. PU is good but a bit messy and I gave up on it as the container usually hardened before I could use it all.The real strength of small boxes like this comes from glueing in a plywood base into a rebate at the bottom and 9 mm will allow plenty of depth for that.

I think we are both assuming what tools are available. .
Pu is messy but crazy strong. I gave up on titebond and gorrila glue for those reasons unless I'm using it all in one go. I use put or lumberjack pu . Both in a silicone type tube

Sean Farrell · 27-06-2021 1:16am

Dowelling worked ok.

Tried the drill press with 5.5mm bit..6mm beech dowel stick from B&Q for 2.50e did the trick.there was a lot of fiddling with the set up...
alignment was an issue...with practise (always forget if its spelt with an "s" or a "c") ...i should improve .
practice!!!

makes perfect as they say.
Tried making plug effect on front facade...not great.
Rebate top was nice design ..thank you for the tip.

Next time I'll be using masking tape when i cut the birch ply with the tablesaw..to avoid the tearout.

Also i might rebate the front panel to connect to the sides next time.

Plus.. I always liked the plug affect on the front of a box..gives nice symmetry. So I'll need to improve on that also.

When i make the box...i treat every side as an individual panel before any joinery is done.
I iron on reversed laser printed images on the sanded sides.
The photos where done on a laser printer.glued on. Then multiple layers of varnish are put on to biuld up protection of the photo. Then wax each panel using 0000 wire wool.

Because i do it this way i have to mask anywhere where the joinery is to be done. Side edges,Plug and dowel holes have to be masked. Wax doesnt help the gluing process...so i make sure to mask the side edges very well.

Its a long process...so any ideas on how i can improve, or make it easier on myself would b great .

I think I'll invest in a dowlling jig...The pin nailer is out of my budget for now.
Now to make the next enhanced better model...maybe with mitres recipio...ok..that'll be further down the road tbh.

recipio · 27-06-2021 10:36am

Sean Farrell wrote: »

Now to make the next enhanced better model...maybe with mitres recipio...ok..that'll be further down the road tbh.

Thanks for posting the photos Sean. The ply looks more like 12 mm - maybe a trick of the camera ? ! If you like dowels you might check out a little known system called 'Millers Dowels' available on Amazon. They come in three sizes and have a dedicated bit. Their big advantage is that they have a shoulder on the top of the dowel which pulls the wood into place when hammered home.
Splintering of the ply is caused by lots of things - a sharp blade will help.
Miters are tricky. Everybody is making splined mitre boxes on YouTube but they are not that strong. Better to make a crosscut sled for the table saw ( if it has a slot in the table ) and mill a groove across the face of the miter. Glue in a loose tenon when assembling. That's how I do it anyway.:pac:

Sean Farrell · 27-06-2021 1:03pm

Thanks for the reply recipio, my comment about mitering was tongue in cheek, aha...theres a pun there!!Appreciate your advice as always.

The ply is 9mm...not 12.:mad: I can biscuit joint 12mm handily enuf...but 9mm thickness needs a different type of joinery.
Searching online for a self centring dowel jig that can face /edge 9mm stock atm..proving elusive.
I will looking for a new tablesaw blade also..with more teeth..hopefully that'll sort the splintering.

Box is coming along nicely. even thou is a practise one.

recipio · 27-06-2021 1:48pm

Sean Farrell wrote: »

The ply is 9mm...not 12.:mad: I can biscuit joint 12mm handily enuf...but 9mm thickness needs a different type of joinery.

Well, you could use a standard biscuit joiner with a 4 mm blade which would give you 2.5 mm of wood on each side of the biscuit. People refer to 'hollows' appearing when the glue dries due to shrinkage - I haven't ever seen it myself. If you were fortunate to own a Lamello biscuit joiner they do a 3 mm blade and biscuits for thinner material. Something else to save up for.:D

Sean Farrell · 27-06-2021 4:16pm

I use that biscuit joinery on the 12mm stock...00 biscuits ...the standard blade is 4mm thick anyways from what i know. I have made jigs that centre and align perfectly the biscuits.
Photos show that there would be hollows or very close too on the face...wouldnt risk it with 9mm stock.
Ooops did i do it again by showing a photo of my dog.....might i have to delete the images of my beloved young one for fear of having the Canine version of Tusla on my case.
The last photo should keep solve the issue and keep her identity hidden.:):)

Sean Farrell · 29-06-2021 2:35pm

recipio wrote: »

Well, you could use a standard biscuit joiner with a 4 mm blade which would give you 2.5 mm of wood on each side of the biscuit. People refer to 'hollows' appearing when the glue dries due to shrinkage - I haven't ever seen it myself. If you were fortunate to own a Lamello biscuit joiner they do a 3 mm blade and biscuits for thinner material. Something else to save up for.:D

Apologies recipio, I misread your suggestion and my reply was irrelevant.

I'm now trying to centre my biscuit joiner on the 9mm ply.

once i have the jig set up properly..i'll glue up a face edge joint and post the results for the hollow theory. Thanks for your patience.

Calahonda52 · 01-07-2021 9:36am

Sean Farrell wrote: »

Ooops did i do it again by showing a photo of my dog.....might i have to delete the images of my beloved young one for fear of having the Canine version of Tusla on my case.
The last photo should keep solve the issue and keep her identity hidden.:):)

What purpose does this serve and what mindset does it point to in the context of child safety?

recipio · 01-07-2021 4:20pm

Sean Farrell wrote: »

Apologies recipio, I misread your suggestion and my reply was irrelevant.

I'm now trying to centre my biscuit joiner on the 9mm ply.

once i have the jig set up properly..i'll glue up a face edge joint and post the results for the hollow theory. Thanks for your patience.

I was going to suggest using plywood biscuits instead of compressed beech ( to avoid hollows forming ) but can't seem to find them. Maybe they are out of production.? Those slots look a little too big - I'd imagine a no 10 biscuit would do the job but of course you gotta set the joiner to the right depth.:D

Sean Farrell · 02-07-2021 11:07pm

recipio wrote: »

I was going to suggest using plywood biscuits instead of compressed beech ( to avoid hollows forming ) but can't seem to find them. Maybe they are out of production.? Those slots look a little too big - I'd imagine a no 10 biscuit would do the job but of course you gotta set the joiner to the right depth.:D

The smallest standard #0 biscuits out there are 47mm x 15mm x 4mm...so i presume an 7.5mm slot on both the face and edge would be the depth of cut when the biscuit joiner is on the #0 setting.
The joiner blade actually cuts 1/32" ( sorry US website info) beyond the 7.5mm slot as well. You'd be left with a max of 1.5mm to spare on the face side..no way that can work. Even thought of pairing the biscuit down and try to reduce the depth of cut with the joiner....a bit fiddly...but still possible with a lot of attempts. But a lot of hard work.
There are FF biscuits that are 10mm width....but the blade would have to be changed to a smaller one.
US websites sell the ply biscuits..thanks for the suggestion recipio. There is also a range of biscuits that have a thickness of 2.4mm . again the joiner would need a thinner blade.
I think I'll pass on this road i'm going down here with the biscuit joiner...I just received the dowel jig and working out how best it might help the alignment on my 9mm stock. I'll post photos of the result soon.

recipio · 03-07-2021 10:34am

Sean Farrell wrote: »

The smallest standard #0 biscuits out there are 47mm x 15mm x 4mm...so i presume an 7.5mm slot on both the face and edge would be the depth of cut .

That's 7.5 mm deep of course and yes, the slots are a little oversized to allow a bit of wriggle room. Again if the ply is 9 mm - deduct 4 for the slot you are left with 5/2 or 2.5 mm each side of the biscuit.
I was just wondering if the ply biscuits would not take up glue like the compressed beech would and prevent 'telegraphing' of the biscuit. They are available on Amazon under the 'Silverline' brand. Another idea is to use PU glue - I'll experiment when I get some 9 mm ply !
Dowels should be OK - I presume you will use 6 mm into the 9 mm ply if the jig will allow.:rolleyes:

Sean Farrell · 03-07-2021 12:09pm

Yea...i realised as i went to bed last nite that the smallest drill hole on the jig I bought is 6mm.( i couldnt sleep!!:rolleyes:).
tried it on the 9mm....no chance..left with 1.5mm each side. Another tool to hide in the cupboard...theres quite a selection there now!!!
In fact it'll work well on my 12mm/15mm boxes. so it'll get lots of use. And I like the symmetry of plugs and dowels on what i do. see photo.

...so i'll try make a jig with the drill press to accomodate 4mm dowels...yawn..sorry i'm getting obsessive about this but i'm not giving in.

Thanks for the advice on the ply biscuits....but i found that the #0 biscuits setting on my Makita PJ700 cuts too deep on the back face side...what u suggested would work on the edge side recipio.as 4mm slot the 2.5 each side...but the face side of the box is a different story, you'd get the 2.5 mm each side all right...but the blade cuts 7.5 plus the extra into the 9mm face. Your left with circa 1mm ( a little under a veneer layer of ply).
...i hope u have better luck than i did..and thanks for having a go.

03-07-2021 12:49pm

Why are you messing around with this approach?

Miter the joints, throw in some biscuits and be done with it.

Or if you for some reason need to butt join the corners and can’t plunge shallow enough using the BJ, add a 2mm perspex shim to the fence or adjust the depth stop screw to suit.

Or get a slot cutter for your router and use the edge fence.

The dowels are fugly IMHO.

recipio · 03-07-2021 2:28pm

JayZeus wrote: »

Why are you messing around with this approach?

Miter the joints, throw in some biscuits and be done with it

The dowels are fugly IMHO.

Putting biscuits into 9 mm mitred ply is well nigh impossible. Its tricky enough with 12 mm stuff. The OP is experimenting with techniques appropriate to his experience.His BJ should have a depth adjuster to facilitate small biscuits although it would be a tight fit. If you are OK with butt joints then I don't see any downside to exposed dowels. It's all a matter of taste.

Sean Farrell · 03-07-2021 3:39pm

Yes.i perfectly agree with you.its a fugly approach with the dowels...

but i do like the exposed dowel look. I could put recessed screws in and add a plugs...but its not the way i want to do things( sorry i'm a bit eccentric) and I'm learning.

I made a jig that perfectly aligns 12mm stock for biscuit joining the type of boxes that i make. I thought i'd make something similar to accomodate 9mm...

I did think of doing stopped grooves on the router table. its an option. and i'm in the process of making a zero tolerance insert plate for my tablesaw. So i could work something there.

In the meantime I'm gluing up my dowels...I guess the symmetry of the process just gets me!!! these ones cant be seen. its a test piece...and my alignment will improve.

The face sides of the 9mm boxes will have a decoupaged image on them which will involve a lot if varnish layers and wax on top too. For some reason i thought that i'd leave the joinery till last as the whole decoupage process of each side before gluing up would be the best approach.

So i could be careful masking around the edges to avoid problems if i butt jointed them...but i thought biscuit or dowel joinery would strenghten things.

Photo here shows the outcome of how i biscuit jointed 12mm stock.

Made templates so as i could make rebates to accomodate glass and photo and backing on each side of boxes...It took a while but the templates are well made and should be durable enuf for a few years(hopefully)

Thanks for everyones ideas so far.

Sean Farrell · 06-07-2021 12:47am

I have noticed that i do blabber a bit ...so I'll be brief as best i can be!! and let the photos do the talking.
Thanks for tips from JayZeus and Recipios support as always.

Telegraphing on front face occured on 9mm with #0 biscuit setting..next time i'll fiddle with the depth stop.

Used two 2mm perspex doubled them up for 4mm shim for biscuit alignment.Thanks JayZeus for the tip and for curing my obsession with trying get perfect centring for God knows why!!

Used #10 setting on joiner to get a cut thru result on face...might use it as a design feature on my next box...I'm not joking.

As for my redundant dowel jig I bought...well i made a storage box for it out of cheap ply. And i rebated the bottom of the box to accomodate the base..giving it a strength. Thanks Recipio.
At this stage I wish i had a pin nailer.

9mm birch ply box...need advice..help

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