Use of 4mm Dominoes in 1/4" or 5/16" Stock

[grbmds]

Has anyone ever used 4mm Dominos to join 1/4" (6mm) or 5/16" (8mm) stock? The wood is walnut and the 2 pieces would be about 16" long, joined along the grain.

This is something I would not normally do because I understand the ordinary thickness requirements for mortise and tenon joints and that the wood is not really thick enough. However, I would like to do it because of ease of alignment during the gluing process.

Just wondering if anyone has successfully done this without blowing out the face of the wood or having the faces of the joined pieces bulge from the inserted Dominos after gluing. If not, I may try it anyway on some scrap just to determine if it will work unless someone warns me that it is inherently unsafe to attempt to cut a Domino slot in wood this thin.

Any other suggestions (if using the Domino would absolutely not work or be unsafe) for aligning the glue joint to get a perfect fit?

 

[bobfog]

Has anyone ever used 4mm Dominos to join 1/4" (6mm) or 5/16" (8mm) stock? The wood is walnut and the 2 pieces would be about 16" long, joined along the grain.

This is something I would not normally do because I understand the ordinary thickness requirements for mortise and tenon joints and that the wood is not really thick enough. However, I would like to do it because of ease of alignment during the gluing process.

Just wondering if anyone has successfully done this without blowing out the face of the wood or having the faces of the joined pieces bulge from the inserted Dominos after gluing. If not, I may try it anyway on some scrap just to determine if it will work unless someone warns me that it is inherently unsafe to attempt to cut a Domino slot in wood this thin.

Any other suggestions (if using the Domino would absolutely not work or be unsafe) for aligning the glue joint to get a perfect fit?

10mm is the thinnest I'd attempt at a push. Solely for alignment it might be worth experimenting with the 8mm as an exercise, but wouldn't consider 6mm stock in a month of Sunday's.

 

[GarryMartin]

Table saw and splines.

 

[Jesse Cloud]

Even if you can cut the mortise and install the domino (without glue for less chance of bulge since you are just using for alignment), the finished piece will be pretty fragile.  Any pressure on the assembly may force the thin mortise walls to break - a real bummer after
all the work of building your project.

 

[grbmds]

Table saw and splines.

I thought of that but, since it can't show on  the outside, I'd have to cut something like a "stopped spline" along the grain.

 

[grbmds]

Even if you can cut the mortise and install the domino (without glue for less chance of bulge since you are just using for alignment), the finished piece will be pretty fragile.  Any pressure on the assembly may force the thin mortise walls to break - a real bummer after
all the work of building your project.

It's a rather simple Frank Lloyd Wright style table lamp (similar to a lamp he made for Falling Water). There is a bottom where the light socket is wired and comes through around which the 2 sides are assembled so, on the bottom, at least, there would be something to anchor the sides against.

 

[GarryMartin]

I thought of that but, since it can't show on  the outside, I'd have to cut something like a "stopped spline" along the grain.

Small bit in a router table and spline?

 

[rvieceli]

You really shouldn't need them. Try using cauls to keep the pieces aligned. Use packing tape in the caul face to keep the glue from sticking.

 

[grbmds]

Here are 2 pictures; one of the FLW lamp itself and one of a similar, simpler version.

 

[Michael Kellough]

You really shouldn't need them. Try using cauls to keep the pieces aligned. Use packing tape in the caul face to keep the glue from sticking.

Ditto. If the mating pieces are jointed properly the glue will be more than strong enough and you won't need much clamp pressure. If they're a perfect match you can pull the pices together with stretchy tape like 2" masking tape.

Whatever spline you put in reduces the surface area of the glue joint. You can't recover that by gluing the splines because the "good wood" will swell and if you sand before it thoroughly dries you'll get concave areas where the glued spines are.

 

[grbmds]

You really shouldn't need them. Try using cauls to keep the pieces aligned. Use packing tape in the caul face to keep the glue from sticking.

Ditto. If the mating pieces are jointed properly the glue will be more than strong enough and you won't need much clamp pressure. If they're a perfect match you can pull the pices together with stretchy tape like 2" masking tape.

Whatever spline you put in reduces the surface area of the glue joint. You can't recover that by gluing the splines because the "good wood" will swell and if you sand before it thoroughly dries you'll get concave areas where the glued spines are.

I will experiment on some scrap. I am just planning ahead. Although I've seen that done, I've never actually done the taping method. I assume that the masking (or other) tape must be very tight to make this work. I use the good blue and green kind for a lot of things; just never this.

Thanks for the suggestions. I didn't really believe I could Domino them together and was just hoping that someone had already tried and either failed or been successful so I'd know.

 

[Holmz]

I thought of that but, since it can't show on  the outside, I'd have to cut something like a "stopped spline" along the grain.

Small bit in a router table and spline?

People complain that biscuits are outdated, but if you found one to borrow it also makes narrow cuts and the biscuits are like narrow dominoes.
They may work here??

 

[Birdhunter]

If the back side of the joint doesn't show, You could use thin aircraft plywood as a backer along the joint It would add strength and provide alignment.

 

[grbmds]

I thought of that but, since it can't show on  the outside, I'd have to cut something like a "stopped spline" along the grain.

Small bit in a router table and spline?

[member=40772]Holmz[/member]  You know, I have a Dewalt biscuit joiner and it is buried so far under all my tools I didn't even thing of it. It might work as long as I don't glue them in and just use it for alignment.

People complain that biscuits are outdated, but if you found one to borrow it also makes narrow cuts and the biscuits are like narrow dominoes.
They may work here??

 

[grbmds]

If the back side of the joint doesn't show, You could use thin aircraft plywood as a backer along the joint It would add strength and provide alignment.

[member=15289]Birdhunter[/member] Thanks for the suggestion but everything shows.

 

[ear3]

Could you use a slot cutter on router table to make the channel for the stopped spline?

 

[bertv]

Glue only is quite enough to make the construction. Positioning is the problem, I guess. My dad used a trick involving very thin nails (or even pins he borrowed from my mothers sewing kit) and a corresponding drill bit. One snaps of the heads of the nails or pins and uses them as one would use dowels.

 

[Michael Kellough]

Glue only is quite enough to make the construction. Positioning is the problem, I guess. My dad used a trick involving very thin nails (or even pins he borrowed from my mothers sewing kit) and a corresponding drill bit. One snaps of the heads of the nails or pins and uses them as one would use dowels.

Forgot about that.

The thicker the nail the more you have to be conscious of the chisel point made by cutting the nails. You want the chisel to be perpendicular to the grain direction so it isn't levered by biased grain that shifts the panels out of alignment.

Insert the pins into one panel about 1/4" deep (as square as you can, maybe drill pilot holes) and snip the protruding part off so that about 1/8 to 3/16 remains. Then apply glue and press/clamp the panels together (between cauls to keep them co-planar).

 

[grbmds]

Thanks for the suggestions. I think I will just use masking tape to fold the sides together. The bottom should be OK because I can use the bottom piece to keep the sides in place while the glue dries. The Dominos would have only been for positioning anyway since I'm sure they would have swelled enough with the glue to cause surface problems on stock that thin.

I'll just have to experiment with some scrap first so I don't ruin good walnut (even though it is a small amount).