1 April 2017 at 11:24 am #310781jcatParticipant
I was wondering about laminating a dining table top, as I’ve only discovered Paul and hand woodworking in recent times I’ve always power routered a tongue and grove joint on the long grain edges. I’ve noticed many factory made solid timber furniture in the stores are also tongue and groved or finger jointed, I was wondering if long grain edge just butted up to the next board is sufficient with PVA glue as I’ve seen hand woodworkers do or is this prone to cracking splitting etc? In my case I’ll be making a dining table top with an Australian hard wood 1800mm x 1100mm x35mm recycled timber that should be very dry (I don’t know much moisture percentages) I’m going to finish it with polyurethane so it should seal the timber from further moisture penetration.
Thanks in advance
1 April 2017 at 1:00 pm #310784Hugo NottiParticipant
- This topic was modified 5 years, 3 months ago by jcat.
So you want to make your boards longer, endgrain to endgrain?
If you are concerned about stability (heavy meals or screwing in light bulbs on the lamp above), you can do groves and toungues. You can also increase the size of the glueing faces by making skewed cuts (i.e. upper end shorter than lower end or vice versa). I would even consider hide glue, because you can use a thin mixture to saturate the endgrain before actually glueing the faces together. The final glueing will soften the glue in the endgrain and you end up with a large glue structure. Aternatively, use epoxy that takes long to dry, so it can form a similar structure inside the wood.
But this is just theoretical thinking, I haven’t learned this and I haven’t made actual comparisions on real joints.
This, I got from woodworking videos: If your wood is very dry, consider storing it in an area with a humidity similar to your dining room. The dryer the wood, the better it absorbs moisture, and even the tiniest crack in the finish will allow moisture to get it. It usually never gets out again. So, I would even consider not to seal the wood completely.
And finally, moisture, shrinkage and expansion are very complex subjects. There is a lot to learn about how the effects of moisture can be mastered.
Dieter1 April 2017 at 3:02 pm #310786jcatParticipant
Thanks Dieter, No no, not end grain to end grain, sorry if my expression is confusing. I meant side edge to side edge to make up the width of the table top.
Thanks for taking the time though
Cheers jcat2 April 2017 at 12:22 pm #310795Hugo NottiParticipant
I found stub joints to be quite stable. If I cut off a narrow strip across the grain, it can be broken next to the glue-line only, the glue seems to be stronger than the wood itself. I think, tongue and groove is used mostly, when the boards aren’t glued together. For example, if you make a panel inside a frame, the panel isn’t glued. Tongues and grooves will keep the individual boards level.
I know three methods to make a table-top. Don’t rely on the following information, because it might be wrong. I am new too woodworking too!
The simplest one is to join several boards together with glue. If this is fixed onto a frame (aprons), it is fairly stable. It can split, if the wood gets very dry, because the wood cannot move, being fixed to the frame.
The second one adds two bread boards to the ends. These provide extra stability and keep the moisture exchange low. You should read Paul Sellers’ blog about bread boards, it explains a lot! https://paulsellers.com/2017/03/breadboard-ends-draw-bore-pins/
The third one is a rectangle frame with a panel inside, which usually consists of several boards. This might be the most stable construction, it is also used also for doors for example.
In your case, I would use the bread-board method. I suppose, you can cut the bread-boards from the existing timber. And it is fairly easy too.
Dieter4 April 2017 at 4:05 am #310853kevinjamesParticipant
I’ve never had an issue just gluing up. I usually take an off cut and try to break my glue line to test it after. Even with a hatchet right on the joint, and struck with a hammer, I haven’t been able to split one…yet ?
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