Thread: Grade 12 project

bisquit joints are very strong. make sure that your boards have at least 4mm on either side of the bsquit so that when the bisquit swells it wont deform the boards. put glue on the edges too..

bisquits 200mm centres.

you'll have no probs - Bj's are accurate and easy.

post photos when your done.

cheers

Hi Freddo, good luck with your project, I went through this with my daughter a few years ago and we both survived ... sort of!
To get meaningful answers from the forum we'd need to see a sketch to see if the join would be load bearing or could be supported by a divider etc, also is the timber MDF, ply, solid timber or laminated panels such as Portra's pine panels.
It's worth putting a sketch up because some of the forum's wizards will still be getting home from Anzac Day and could be in extremely good or extremely bad humour!
Fletty

everything on my project is solid wood and it would like it to hold the weight of a tv vcr dvd players etc. but i am not able to put a sketch at the moment because my scanner is not working and i have sketches done up at school on a graphics program but i will try and get something organised

Biscuit joins are real strong. They hang together like Sonny and Cher, perhap not, er.........Tom and Nicole, no, er..... Brad and Angelina, maybe not er......... Costello and Howard, let's not go there, er..... I GOT IT.....

Becky and Leyton - wooo hoooo!

What do you need to join?MDF,Ply are available in 2400x1200 mm sheets and it may be cheaper and in the long run easier to just get a full sheet rather than,say,several smaller pieces like the ones generally sold in hardware stores.Check the delivery cost though.
What size is the TV unit?

BTW,Welcome to the forum.Whatever you want to find out...someone here will know and be pleased to help.

I was thinking scarf joint...

(duck back into fox-hole)
Edit..I read "End to end" for "Edge to edge".Whoops.

i got some general messurments here by the way it is a corner TV cabinet 1800
it is in a L sort of shape as well
Depth: 1300mm
sorry it is sort of hard to explain with out a sketch i will try and get one on the forum as soon as possible
thanks for all the advise

Maybe if you can post a link to something similar?

Here's a link to eddies excellent post which may be of assistance.design and technology student needs help - Woodwork Forums

Guys just a quick note, most schools do not allow students to use MDF, as it is carcenogenic!
I am a teacher of D/T and i know our school has this policy in place.

HI Geoff,

I think that the wording in your post confused a few.

I assume that you're joining a sheet of veneered chipboard or MDF

In this case, I'd steer away from biscuits - the veneer is 0.6mm thick, so if you get the two panels slightly out when you join them, you've hit trouble immediately.

If it's from Brims, they may be able to lay up a panel 1800 wide as a one-off, but it won't be cheap.

Alternatively, look to your design. Can you hide a joint behind a (vertical) division in the cabinet somewhere - it's rare that a gap is longer than 2400mm unbroken.

If you want a single piece of timber that wide so it can be the top of the TV unit, then perhaps look at a mason's mitre or mitred return. THis way, your cabinet top stays as a 600mm wide piece of material, which is a far cheaper way to go (as the subject is Industrial Technology, you might be required to mimic industry standard in places, however, I don't know the requirements of the Qld syllabus.)

Anyway, enough said. There's a good text that we use down here, but written for the Qld syllabus by D.Schlyder, from memory, the title is "Furnishing Studies, an Industry Guide." If you don't have a copy already, your school library would probably have at least one copy - I'd take this out from the library and skim read it overnight.

This book should provide you with a lot of guidance.

As well, see if you can get a local cabinetmaking shop to spend half an hour going over your design and discuss with them options to make the thing feasible. Phoning first and explaining who you are and what you're up to, rather than rock up on the doorstep always gets a better response. Most people shouldn't have too much of a problem sparing half an hour for a HSC major work.

Good luck,

eddie

Freddo,
From the way I read your post, "solid timber" I would presume you mean a natural timber ie radiata pine, maple, tas oak etc and not MDF, chip board, masonite or other manufactured material.

If this is the case then a point to consider, large flat (wide) sections of timber are generally not sold as they have a greater tendency to warp and cup. Edge jointing by the use of a biscuit will overcome this by keeping the panels to 200mm width or there abouts. Zeds info is good for "solid" timber (not so good for manufactured woods).

You should apply glue along the edge of the joint, not just the biscuit hole and the type of glue if you want to display the panel (ie its in view) should not creep. This means that once fully cured the glue stays put in the joint and not sort of oozes out over time. Yellow glue is a good product for this type of joint depending on the type of wood. Some woods have a high resin/oil content which makes them more difficult to glue - but I would doubt you would be using these types (tallow wood etc).

Hope this helps

Biscuiting is definitely the way to go - not so much for strength, a good butt joint should be strong enough - but it will help align the pieces and leave you with a minimum amount of cleaning up. Use yellow glue (AV180 or similar) and make sure that there are no gaps in the join before you glue it up. Good luck.

Geoff,
Assuming that the project is solid wood.

If you have access to a 12" or larger disk sander, join the pieces with a taper (scarf?) joint. Clamp a fence to the sander table. The fence should be as high as the wood to be joined and off parallel to the disk. (15 or 20 degrees) see: http://en.wikipedia.org/wiki/Scarf_joint While you're looking there also click on the splice joint link. (I do disagree about the strength of the scarf joint.)

Keep the solid wood along the fence and gently feed into the disk sander. You'll sand a taper about 4 inches long. Do this to each piece of wood. Then just glue the pieces of wood together along the joint. Effectively you're gluing face grain to face grain and the joint should be stronger than the wood itself.