Help with measurment

[mgf23]

Hi Guys

I am undertaking my 1st woodwork project (a chest for the kids bedroom) I have opted to use pine board.

The box will be 700 mm in length and 400 mm wide . The thickness of the pine board is 18mm (I intend to join all the sides using dowels to which I have made a drilling jig)

My question arises when measuring for the base:

Do I calculate the size of the board for the base by taking the overall length (700 mm) and subtracting the thickness of the sides (18 mm x2) to give me a length of 664 mm.

Using the same method I make the width of the board 364mm. so to get the bottom board of the chest to fit snugly internally I would need to cut a piece of board 664 x 364 mm

Any pointers would be greatly appreciated.

All the best

 

[Chems]

Yes to all.

However I wouldn't make the base of the unit by just fixing it in place at exactly the right size. If the the base board expands, which it will it will force apart the box. Instead I would make the bottom panel 6-8mm wider all around and place this into a 8-10mm deep rebate around the bottom. Either using the pineboard or a man made board like mdf or ply. If you did want to use the pineboard as your base I would rebate the edge of that all around to make a tongue closer to 9mm rather than the full 18mm.

Here are 2 pictures that may explain it better showing a 18mm base board used.

You can download the sketchup here. Its a free google program encase you don't already have it.

Sketchup File

 

[mgf23]

Ahh yes expansion - overlooked that.

Thank you for such a detailed answer and the illustrations are a great help- - rebate is the way to go. Thank you!

 

[Chems]

No problem, be sure to take your camera and document your progress in the WIP section!

Just a note as well, in that picture and sketchup the rebate in the long sides goes all the way to the end of the piece, but in reality that needs to be a stopped rebate on the long sides. I'm sure you already realize this I just wanted to point it out encase my picture led you to make a mistake.

 

[doorframe]

Hi mgf.

Welcome.

Where in Essex are you?

Roy