LumberJocks

Morris Chair bent arm laminations ply thickness

  • Advertise with us

« back to Designing Woodworking Projects forum

Forum topic by Willington_Chuck posted 1019 days ago 1479 views 0 times favorited 3 replies Add to Favorites Watch
View Willington_Chuck's profile

Willington_Chuck

3 posts in 1019 days


1019 days ago

Topic tags/keywords: morris chair lamination

Hi, I’m new here. I’ve been lurking in the epic morris chair thread for a while, but I can’t seem to find the answer to this particular question.

I am building a pair of Morris Chairs from the plans in Wood Magazine issue #112. I’m making them out of qsawn oak. I have a question about the laminations for the bent arms. The plans call for laminating three pieces of 3/8” for a final thickness of 1 & 1/8”.

My original plan was to get down to 3/8” by thickness planing 4/4 stock. I couldn’t find 5/4 stock to resaw into 3/8”, and a few test runs on pieces much smaller than the armrest laminations proved to me resawing two useful pieces of 3/8” stock out of one piece of 4/4 is currently beyond my level of ability.

But, after doing the math, I’m a little unsure of my plan. (2 chairs) x (2 arms each) x (3 plys per arm) = way too much sawdust and waste if I start from 4/4. Besides, if I can do it more efficiently, I’m pretty sure I will have enough leftover qsawn oak to make a nice endtable or ottoman.

So, that leaves me here, with two questions.

1.) How will it effect the finished product to laminate the arms out of 4 plys of ~0.28” thick rather than 3 plys of 3/8”?

2.) When resawing thin pieces like this, it seems pretty typical to end up with two bowed pieces even if you start with something that was milled square. Given that these pieces are destine for a bent lamination anyway, do I need to worry about machining off any bow that shows up after resawing?

Thanks for the help.

-Chuck


3 replies so far

View Alongiron's profile

Alongiron

402 posts in 1318 days


#1 posted 1019 days ago

Good Morning Chuck; Did you rememeber to set yoour clock back? I forgot and got up way to early this morning! Anyway…..I built a rocking chair that was also from a Wood Magazine plan. Here is what I did. I milled down a couple of pieces of QSWO; that I get in rough sawn; to approx 3/4”. I split this up into 3 fairly even stips and then took another piece of 3/4” and split it right down the middle. I use my thin kerf blade on my bandsaw. Here is the secret..when you laminate up your arms, put the 3 pieces from the same board back togeather in the same order and on the bottom use one of the pieces from the piece you split in half. You will not see the joints and you have no waste at all 3/4 + 3/8 = 1-1/8” ! Hope this helps

-- Measure twice and cut once.....

View BobLang's profile

BobLang

98 posts in 2025 days


#2 posted 1019 days ago

1) No ill effects, the arm will be less likely to spring back with four laminations instead of 3
2) Find something else to worry about.

It would be crazy to waste more wood than you use, just because the magazine article said to use 3/8”. There is no perfect thickness for the plies in a bent lamination, there is a range of sizes that work just fine. It’s a dance between making the curve and using available material.

Bob Lang

-- Bob Lang, http://readwatchdo.com/

View CaptainSkully's profile

CaptainSkully

1190 posts in 2184 days


#3 posted 1018 days ago

Bob Lang is definitely someone to listen to in these matters. I always get a kick out of seeing him post here.

I’ve seen lots of bent laminations with 1/8”. They bend easier, the glue allows them to slide and settle around the bending form, you get less springback, there’s less stress on the fibers, and if you choose the wood sequentially from the resawing order, you can barely see the laminations before finishing.

Another trick I’ve used is to glue the thick stock together if the added thickness will yield better resawing. For example, if you can’t resaw 4/4 into two pieces, can you get three useful pieces out of 8/4? There may still be some waste, but it’s not as bad.

-- You can't control the wind, but you can trim your sails

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com

Latest Projects | Latest Blog Entries | Latest Forum Topics

GardenTenders.com :: gardening showcase