Thread: constructing a benchtop

Hey ren

Definetaly use biscuits and you will need to clamp across and also stop it from warping by using clamps to hold it down across the top as well. Carbatec sell a panel clamp set that holds downwards as well as from the sides.

I have found that the best thing to finish it is to go to the local joinery shop and if they do small jobs ask what is the maximum width of thier thicknesser and if the top is wider then make it in two sections (glued and clamped seperately) and have them thickness both the same after they are dry. You can then clamp these two together and orbital sand them flushwhen finished.

good luck

drago

Hi
I cant see the need to re-thickness KD, just buy the thickness you need.
Glue and biscuit them together makeing sure they are flat when you are doing it.
After glueing, start sanding with 120, and work upto 400. 1200 is even better if you can get hold of it.
For the finish you cant go past either, shellac although it can get very shinney, or go with Organoil Interia and put on a hard wax.
For the shellac and wax try here http://www.ubeaut.com.au/ubhome.htm

Oraganoil is from Bunnies.

To hold the top down use buttons, so as the top can move with the weather.
Do a search for buttons.

Cheers, Allan

Hi ozwinner,

my experience with biscuits is that they let the boards move slightly and it is very difficult to get them exactly aligned. Dowels on the other hand dont seem to do this but are harder to get exactly aligned.

perhaps ive just been unlucky.

cheers

drago

Make sure that the pieces are straight down their length otherwise joining boards will not work. Many pieces of DAR timber are bannanas or twisted.
This is a constant frustration for me and the reason many on this forum buy jointers.

My experience has been similar to Drago & Mat.
An alternative to a joinery with a large planer might be somewhere with a large thickness sander. Have a look in the yellow pages for places that supply pre-finished floorboards. It will save you a lot of sanding.

I think everyone has a different opinion on how to go about this job. My preferred way is to glue up without biscuits or dowels or any other joiners. Just put the clamps on sawhorses so you can get at the assembly from underneath, do them up lightly and align from above and below. Then when you are happy, do it up all the way. If you cant get all the boards straight then you have twisted boards in there somewhere which you shouldnt be using anyway. Good straight, square stock which has been well chosen and prepared will align automatically.

Be careful about using PVA with Australian hardwoods. Its not suitable for all hardwoods. Depending upon what you are using, you may need to go to something from AV Syntec or similar.

I remove the excess glue before it dries, from above and below.

Once the glue is dry, I surface with a plane, then sand with an ROS. If the timber allows, you can do the whole thing with a plane and scraper and not sand at all, which will give a classy finish. Before learning to use a plane properly, I used to do the whole thing with an ROS and the results were just fine. If your assembly was a bit rough, start with 40 grit then work right down to 240 removing the spiral scratches as you go. When using the coarser grit, check frequently to make sure you are not making the surface uneven. Rightly or wrongly, I sand across the board on each diagonal first, then along the grain. I find it leads to a more level surface.

Make sure you put some tape over the clamps wherever the timber may touch; or the glue, wood and steel will all react together giving you some nasty black stains in the wood. Happens with many types of glue.

Also, make sure you align the strips correctly. Try to make sure the grain all goes in the same direction, especially if you wish to surface by plane. Most people also prefer to alternate the radial orientation of each board - you can see this by looking at the end grain. That way if longitudinal cupping occurs across several boards they will cancel each other out.

It is actually a very easy task.

Arron

for what it is worth.
I have just finished making a few smaller panels, (for a blanket/glory box).
I used biscuits to join these. As pointed out dowels give more accuracy, but if your'e careful biscuits will give the almost same accuracy, and if ya ain't careful, they give a little lee way.
The big one that worried me was keeping everything flat. A panel clamp was too $$$$ for a mug like me. SO I VERY carefully planed a lump of 90 X 90 (app) hardwood FLAT , then made a mate for it, so when the two were placed together their edges met perfectly. Place one on top of panel one underneath and clamp these with F clamps. Make as many of these as needed for the size of the panel to ensure it don't go nowhere, add some sash cramps to actually join the timber into a panel, and Bob's ya Aunty.

Firstly I'm thinking since the timbers are DAR, its probably best not to plane or sand before joining. ???

I'm not sure if you have the equipment or experience to joint the edges of the boards (flat and square) but I fear that you will end up with visible glue lines if you do not do so.

DAR does NOT mean ready-to-glue-up! It just means a power planer in a factory has done the best it can at the time. But wood dries, expands, shrinks and moves. It is possible to go with it as it is, but then you must accept the imperfections that result.

Some use power jointers. I prefer a hand try plane. Either way the aim is to have timber that will fit together without a visible glue joint (even if the timber can't be colour and grain matched, the join can appear seamless).

I prefer to join long planks with dowels. These require a bit more care than biscuits, but they move less and this is important if you wish to minimise the amount of re-surfacing you wish to do.

Square edges give a flat top (otherwise you will have a curving top, or pull the edges out of contact to square the top). I have a jig somewhere on this forum for handplane use to do just this. Or use a power jointer.

If you plan to smooth the top with handplanes then you must orient all the grain in the same direction (or face much tearout). This is not necessary if you plan to use a sander.

Keep us informed of your progress and, of course, don't forget to post pics of the finished piece.

Regards from Perth

Derek

thanks drago, ozwinner,mat,alex,arron,outback and derekcohen;

you have given me very good advice and I cant wait to get started. I would love to take long service leave and lock myself in the workshop.

it seems the key thing is to ensure the timber I buy is good quality from the start (straight, DAR, select) to make my job easier.

If I decide to use biscuits, is there a recommended distance apart thay should be placed? Or I might try it without biscuits.

thanks again
Ren

I love this forum!!

Originally posted by Ren


If I decide to use biscuits, is there a recommended distance apart thay should be placed? Or I might try it without biscuits.

thanks again
Ren

Place your biscuits about 300mm apart, it is not critical.
When you cut the slots make sure your boards are all in the same orientation ie. all face up or all face down.
Save yourself some grief and invest in some panel clamps, they really do produce perfectly flat glue ups.

Check out these at CarbatecWA
Panel Clamps

or these at Timbecon
Panel Clamps

No doubt you will be able to find something similar in your own locality.