Thanks: 0
Likes: 0
Needs Pictures: 0
Picture(s) thanks: 0
Results 1 to 8 of 8
-
1st July 2015, 06:14 PM #1Senior Member
- Join Date
- Aug 2013
- Location
- melb
- Posts
- 187
The strength of Hardwood long beam with Joins?
I was looking at Merbau & it has zigzag finger joins every metre or so in the beam. Would 2M length 50x50mm with a join in middle be as strong as 2M of Merbau with no join?
If you wondering what this is for, just an upright beam with a vertical extended steel support on top to hold some weight around 40KG. Something like merbau with no joins would be plenty strong. I just don't trust these joins.
-
1st July 2015 06:14 PM # ADSGoogle Adsense Advertisement
- Join Date
- Always
- Location
- Advertising world
- Posts
- Many
-
1st July 2015, 06:47 PM #2Intermediate Member
- Join Date
- Oct 2012
- Location
- Geelong
- Posts
- 41
A couple of years back i had the opportunity to go on a tour of a timber mill in Colac, one of their value added products was finger jointed radiata pine panels and posts like the one you described. Samples were regularly taken and stress tested. Pretty sure every sample i saw in their testing lab had failed in the timber and not at the glue join.
If you are loading the post vertically the stress on the joins will be compressive so i wouldn't think it would be a problem.
-
1st July 2015, 07:28 PM #3
50 x 50 is pretty solid
is your intended use a beam (i.e. horizontal) -- or a column (i.e. vertical)?
if a column is the 40kg load axial (i.e. down the centre of the column) -- or off axis?regards from Alberta, Canada
ian
-
1st July 2015, 07:33 PM #4Senior Member
- Join Date
- Aug 2013
- Location
- melb
- Posts
- 187
-
1st July 2015, 08:39 PM #5
I don't think there will be a problem.
However, do you have a sketch of how you intend to use the column?
What provision have you made to resist buckling over the 2m length? braces, or struts, or shelves, or ...regards from Alberta, Canada
ian
-
2nd July 2015, 05:57 PM #6Senior Member
- Join Date
- Aug 2013
- Location
- melb
- Posts
- 187
-
2nd July 2015, 11:33 PM #7
that's what would worry me.
The duration of the load is not really relevant.
However, the strength of any post (or column) declines rapidly as the post bends and even a little nudge to the bow can induce catastrophic failure
see attached diagram
50 x 50 Column.jpgLast edited by ian; 3rd July 2015 at 12:26 AM. Reason: add diagram
regards from Alberta, Canada
ian
-
15th July 2015, 06:27 PM #8Senior Member
- Join Date
- Aug 2013
- Location
- melb
- Posts
- 187
Hi, nice diagram.
I decided to back the weight off a bit to 33kg, here is a diagram of top section, I just had a question about the support.
The blue support will be bolted into the wood where indicated at red line, I'm wondering what is the minimum thickness bolt needed for strength? I would like to go 6mm as any wider & the width of the wood suffers. What about two 6mm bolts one on top of the other? would the load spread on both bolts evenly?
thanks
Similar Threads
-
Joining long lengths MDF with biscuit joins
By RussellB in forum FURNITURE, JOINERY, CABINETMAKING - formerly BIG STUFFReplies: 6Last Post: 15th July 2014, 11:21 AM -
cutting extreamly long recycled hardwood
By weisyboy in forum SMALL TIMBER MILLINGReplies: 5Last Post: 8th August 2013, 08:19 PM -
eBay- how long is too long to wait?
By jack620 in forum METALWORK FORUMReplies: 20Last Post: 17th December 2012, 08:38 PM -
reconditioning a windmill (long long story here)
By .RC. in forum METALWORK FORUMReplies: 35Last Post: 29th September 2012, 07:14 PM -
Laminated Hardwood Beam
By Burnsy in forum TIMBERReplies: 4Last Post: 23rd April 2008, 10:15 PM