Help with homework please

[sinners]

Hey guys new here obviously lol. i searched all through google and couldn't find a legit answer to a question on one of my assignments for wood so i bring it here :).

When log of timber arrive at the saw mill for cutting into planks, there are various arrangments the log can be sawn into. Illustrate 2 methods and discuss advantages/disadvantages of each arrangement.

If some one could provide a link to the answer or wants to take the time to answer it themselves it would be much appreciated.

Thanks sinners

[Sigidi]

Sinners welcome and as way of not doing your homework for you... look online using Keywords "backsawn" and "Quartersawn" any q's after researching that, drop us a line

hope it helps

[sinners]

thanks sigidi i didnt actually think any one would 'tell' me the answer

cheers siners

[derekh]

Have a look at http://www.radialtimber.com/radial.html for Radial milling.

[Burnsy]

Sinners, post your answer after you have done the research as some of us here would appreciate the knowledge. Also it gives others who are in the know to check it for you.

Cheers,
Burnsy

[Sigidi]

thanks sigidi i didnt actually think any one would 'tell' me the answer

cheers siners

That's ok mate, just around here others have asked similar questions and been slammed, (otherwise it is a great place!!) so I wanted to get in first and try to show (others) you may not have been just asking for someone to do your homework for you, this way hopefully you have side stepped any 'bad press'

And a great idea of posting your answer to the Q before handing it in, then you'll have the best chance of getting it 'reviewed' before handing it in.

Good luck

[glock40sw]

G'day.
The log cutting pattern is controlled by the actual log specie. Some Timber (Vic ash) Has to be Quartersawn due to the high shrinkage during drying.

We cut mainly Backsawn for all our hardwoods due to faster processing and better recovery out of the log.

When a log is milled, it ussually has the 2 outside round backs removed first. Then it is dropped and turned 90deg. it is then redogged and cut into 28mm thick slabs untill the center cant is 110mm wide. It is then dropped and sent to the re-saw bench. Here the center cant is cut into 28mm thick slices. Thus ending up 110x28mm. this is the size we cut to produce 80x19 T&G flooring. The 28mm slabs are sent to the multi-saw. this has 6 saws in it (multi-saw....get it???) It cuts the slabs into 110mm wide slices. This also produces 110x28mm boards.

If you go to www.timber.org.au (http://www.timber.org.au) you will be able to download sawing trial reports that explain how the different types of sawing patterns affect the end use of the timber.

[sinners]

So far i have come up with that back sawing is when the growth rings are parallel to the board face. It is easier, cheaper and less laborious to produce. Quarter sawn is when the growth rings are at right angles to the face of the board. It is alot harder to produce and this therefore makes it fairly hard to find and expensive.

Looking at a few diagrams i would think that back sawing produces less wood and it is weaker compared to quarter sawn. is this true? Quarter sawn wood would be stronger i would assume because the growth rings are running at right angles. is this also true?

I have not officially wrote anything up but once i get all the 'correct' (so much wrong stuff out of the internet) info i will post what i wrote.

thanks

sinners

[KevM]

Forget about using the word stronger, investigate timber stability.

Also look at tangential and radial shinkage.

[glock40sw]

Wrong... Quatersawn is weaker. If you hold it in each hand you can break it in half ( Like breaking a scotch finger biscuit). You can't do that with Backsawn boards.

[sinners]

thanks for all your help so far guys

[charlsie]

sinners ,everything the blokes have told you in the this post is spot on .all you have to do now is ask for a demonstration. there's a heap of people willing to show you how a log gets cut up. how to back saw, quarter saw and any other questions you might want answered. i'm in the yarra valley victoria and if you are local come down and cut up a log to see how its done. this gives you real expierience on how a log is cut and its uses. i'm sure any one in your area would be happy to extend the same offer
regards charlsie

[Sigidi]

As Charlsie said, I'm more than happy (if you are interested and in the area) for you to have a look. I operate from Bris-Vegas to Gympie.

Most often a picture is worth a 1000 words, and as mentioned a small amount of time invested with anyone here will produce a wealth of knowledge unsurpassed by books or the internet. Don't get me wrong the net and books are useful tools, but I'm expecting if you are doing assignments on wood then a deeper understanding of the process will be a great advantage.

Oh Crap, listen to me preaching like some know it all:) anyway I'm sure there'll be someone around you who can help with some preactical experience.