[RichT]

Laminated wood is MUCH stronger and MUCH less likely to warp than a single solid piece of wood.

- Oughtsix

That statement doesn't match my experience. I could go on about other claims as well. Do you really believe two 3/8" pieces of pine glued face-to-face is stronger than a single board? I strongly suggest you try it. I know what will likely happen, but you'll get a good lesson from doing it.

Just out of curiosity, how many residential doors, bi-fold or otherwise, have you built? Post some photos if you have them.

 

[RichT]

Interesting Rich, I would lay all the styles side by side and used knife nicks to align all rails. Never dawned on me to make as one and rip it. Nice door, what are those panels on top made out of?

- controlfreak

Those are juniper latillas we picked up on a trip to Santa Fe. We wanted to match the vanity in the room.

My wife does that part. There's no way I have the patience to cut and fit all of that.

 

[RichT]

Just for fun, I went looking for some numbers. As it turns out the data refutes the statement that "Laminated wood is MUCH stronger" than a single solid piece of wood.

I found this PDF from the USDA Forest Service web site. Here is a quick screen grab from it:

You can see that plywood has a lower MOE an MOR than any of the woods. Moreover, they aren't even listing woods with the highest values. For example bloodwood has a MOE of 20.78 GPa and a MOR of 174.4 MPa.

 

[Oughtsix]

Laminated wood is MUCH stronger and MUCH less likely to warp than a single solid piece of wood.

- Oughtsix

That statement doesn t match my experience. I could go on about other claims as well. Do you really believe two 3/8" pieces of pine glued face-to-face is stronger than a single board? I strongly suggest you try it. I know what will likely happen, but you ll get a good lesson from doing it.

Just out of curiosity, how many residential doors, bi-fold or otherwise, have you built? Post some photos if you have them.

- Rich

I glue up laminations all the time and yes they are definitely much stronger than single pieces of wood. 4 plys of 3/8" boards will definitely stay straighter than a single piece of 1.5" lumber as well as be considerably stronger. There are no weak spots in the grain that go all the way through the board with laminated lumber.

I am quite confident that Iam not the only one to laminate wood for strength. I think howard huges even built a pretty famouse air plane at the tail end of WWII that took advantage of the strengths of laminated wood.

 

[RichT]

I glue up laminations all the time and yes they are definitely much stronger than single pieces of wood.

- Oughtsix

So the US Forestry Service is wrong?

 

[Oughtsix]

I glue up laminations all the time and yes they are definitely much stronger than single pieces of wood.

- Oughtsix

So the US Forestry Service is wrong?

- Rich

Sorry Rich, you aren't worth my time to have a fight with. LOL!

 

[RichT]

So the US Forestry Service is wrong?

- Rich

Sorry Rich, you aren t worth my time to have a fight with. LOL!

- Oughtsix

You can't refute the US Forestry Service, and instead choose to insult me? I get the picture.

This matter is settled.

 

[northwoodsman]

Rich - plywood isn't the same thing as the laminated boards that Oughtsix is talking about. Plywood layers are at the very most 1/16" thick. Plywood in general is made up of crappy "filler" wood that is used in the inner layers that is full of holes, voids, mismatched pieces, etc., you aren't going to have a strong product. When the layers are that thin they also aren't going to prevent warping as we see in much plywood that is sold today. If you take 3/8" thick layers and carefully match them so that the warping tenancies are back to back, then clamp them on a flat surface using high quality glue, you are going to have a very solid and stable piece of lumber with little or no stress to cause warping. Why do you feel that you have to argue with almost everyone on almost every subject? This is a woodworking forum where we share ideas, experience, wins, losses, and solve problems. It's not a debate forum. Don't be the school bully that nobody likes and everyone fears. Everyone has their own opinions and experience that has worked for them. It may work well for someone else also. There are multiple ways you can get to the final result that are acceptable and will work for people based on the tools and materials that they have available to them.

 

[RichT]

Rich - plywood isn t the same thing as the laminated boards that Oughtsix is talking about.

- northwoodsman

Here's a quote from him in post #19, second paragraph: "Plywood is laminated wood hence its strength and dimensional stability."

I'm satisfied with the data in the Forest Service document I linked to, so until someone posts data to the contrary, I'm sticking with it.

And, sadly, you chose to go here:

Why do you feel that you have to argue with almost everyone on almost every subject?

Why do you feel it was necessary to butt in? Did I tell anyone they weren't "worth" my time? I cleared up some misinformation and was insulted for my effort. I think you're barking up the wrong tree.

 

[Sylvain]

When speaking about laminated lumber, we should look in the table at the line "glued laminated timber" which shows value inferior to the value for the wood listed.

Now of course the comparison makes only sense for the same dimensions of the cross section.

Glued laminated timber is nevertheless irreplaceable for long span beams; one has of course to use the correct cross section's height and thickness.

The table is for bending properties which I don't think are critical for this very project.

 

[LeeRoyMan]

This is a woodworking forum where we share ideas, experience, wins, losses, and solve problems. It s not a debate forum.

- northwoodsman

I strongly disagree.
This is an open forum and is for debate, as much as anything.
Is there a rule somewhere that I missed that reads not to have debates?

I have learned more through debates, arguments, or whatever you want to call them than I have with the common I think this and I think that conversations.
Good debates (arguments) bring up a lot of information that I can determine to use however I want.

Now to add my 2 cents to the debate,
If it were me I would use solid stock just like it has been done for centuries.

 

[controlfreak]

I think there are differing "laminated" products that would have different values. I don't think you could compare plywood to an engineered laminated structural beam that is used to span longer rooms for support and to carry a significant load. All that said I think two boards laminated to make a leg on my bench are stronger than a solid board due to the differing grain pattern where a weakness is only in 50% of the board or 33% if using three. Cutting all of these into 1/8" strips in the hope of getting more strength is a fools errand.

 

[Oughtsix]

I guess I just need to give in and pay for a subscription to SawMillCreek to find some knowledgeable, insightful and helpful discourse. If you guys ever clean up your board and get rid of the BOZO factor drop me an email!

I send to all of you my best wishes and happy woodworking! -so long!

 

[controlfreak]

I guess I just need to give in and pay for a subscription to SawMillCreek to find some knowledgeable, insightful and helpful discourse. If you guys ever clean up your board and get rid of the BOZO factor drop me an email!

I send to all of you my best wishes and happy woodworking! -so long!

- Oughtsix

I think several members have shared their knowledge, or possibly lack there of, but that is what a community is. But resorting to calling others "BOZO" and picking up your toys and going home adds nothing meaningful to this community other than your departure.

 

[Sylvain]

I guess I just need to give in and pay for a subscription to SawMillCreek to find some knowledgeable, insightful and helpful discourse.
- Oughtsix

I don't see why people would be more knowledgeable because the site is a paying one.

 

[Tony_S]

Seems a few here are confusing the terms 'strength' and 'stability' in reference to solid wood and manufactured(engineered if you like)wood products. They and their characteristics aren't even remotely the same thing.
Saying 2 sticks of wood glued together is more better because plywood is more better and LVL's are even WAY more gooder than plywood…is ridiculous.
In a VERY general sense, are 2 straight grained pieces of wood that are glued together to the same net dimensions as one solid piece of wood 'stronger'? No. End of story.
Is it more 'stable'..? Likely, but not a given since there are so many different factors involved. What are the dimensions…the type of lumber, the cut of the lumber, the orientation…where is the lamination?
The hodgepodge of unfair comparisons in this thread would take a week to dissect.

 

[controlfreak]

I wasn't trying to compare the two other than they are both laminated. I guess the chart posted was measuring strength but I really didn't scrutinize it very close. I doubt anyone on this site would question stability of plywood. Now that you mention it what kind of hinges should the OP use for bifold doors made from Lam beams? Very solid doors but you better watch your fingers when you close them.

 

[Sylvain]

I would only use laminated wood for door stile and rails if I could not find a suitable piece of wood, if if it would be too expensive or, on special occasion.

I have used laminated wood for the rails and stretchers of my Moravian workbench because I was using free recycled wood.

I have used laminated wood to add a rail to an existing door (using false tenons and gluing the two half rails on each side of the false tenons)

adding the second layer:

with my first panel:

 

[je_an]

There was a lot of heated discussions on this post. Thanks everyone for your contributions. I thought I would post what I ended up building. It's been a year and the door panels still look pretty good. I for some reason, put the door knobs too high. I have been meaning to fix that but haven't gotten around it it yet. Other than that I am pretty happy with the results.

 

[PCDub]

They look great! Am I correct in thinking you put ply over the four frames, then added molding to make them look like frame & panel? I think it worked out well!