Need some help here plz.

[Wongdai]

Continuing on from my WIP http://www.woodworkforums.ubeaut.com.au/showthread.php?t=83664

My idea was to:
(a) Get some timber - done
(b) Get it dressed - done

I thought I would start with the top first, so I have docked a suitable quantity of timber to length.

Before gluing it all up I though I would do a practice clamp up. Pictures follow:

So far so good....

http://i111.photobucket.com/albums/n123/wongdai/wood/IMG00024.jpg

Uh oh...

http://i111.photobucket.com/albums/n123/wongdai/wood/IMG00025.jpg

I'm starting to get a headache!

http://i111.photobucket.com/albums/n123/wongdai/wood/IMG00026.jpg

As you can see it is all over the place. Is this normal or was it a bad job of dressing?

What is the best course of action now? Should I just glue it up and then use the router planing method to get it flat?

All advice is appreciated.

Wongdai

[Ron Dunn]

Where / how did you get the timber dressed? That is a shocking job.

[Ron Dunn]

Hmmm ... just realised that I can't see the lower edge of the boards where they don't align ... are the boards different sizes and shapes (as it appears in the picture), or has twisting and warping just pushed them out of alignment?

If they're different sizes and shapes then it is a terrible job of stock preparation.

If they're just out of alignment that isn't too unusual. Try using dowels, biscuits, etc. to help with the alignment. Traditionally you'd clamp your way along, using brute strength and a hammer to pull it all square, but mechanical alignment is much more simple.

[m2c1Iw]

Woodworking rule #1 : Start with straight and square stock.

By the look of the pics I have to agree with Ronn a terrible job of dressing or the boards are way too green and have warped since machining.

To answer your question, stuff that has been jointed and thicknessed should only require a smoothing plane to remove the knife marks from dressing. I would take them back and have them redone if there is enough material otherwise you will be practicing your hand planing skills for some considerable time.:roll:

Oops I should have read your other post first I realise I have just insulted you my apologies. The stock came from a demolition yard so it should be well seasoned and dry perhaps check the moisture content anyway. The apparent cupping and twisting usually occurs after resawing not after jointing. Another small point is thickness your boards first then dock to length to remove the thicknesser snipe (thinner bit at the end)

Good luck
Mike

[weisyboy]

are they siting on that metal bar?

did you tell them to just dress them or joint and dress. some places wont use a jointer it not asked.

[Wongdai]

Thanks all

Well, my FiL did them for me, and to say he is sometimes a bit rough and ready is an understatement. Saying that, he probably did a bitter job than what I could do.

The were firstly planed, and then thicknessed. They are all meant to be square and the same thickness (different widths and lengths though).

I've got them so they butt up edge-wise to each other fairly well, as I attacked them with my number six.

Not sure if I should ask to borrow the planer and try and redo them, or if I should glue them up and use the router planing technique.

Again, any advice appreciated.

Wongdai

[Wongdai]

ps I'm almost positive they have not warped or twisted since planing. They come out of the root of a 50 year old house.

[Ron Dunn]

I'm a bit confused by the 3rd. board from the left in the second picture. It looks like it tapers across the width of the board. Is this correct, or is it just that the board has twisted?

[Swifty]

Hi Wongdai,

You could join the plans with dowels or with biscuits. Easier if you have a biscuit joiner as they allow for a little slop. Then get some bar clamps (I got mine from Carbatec in Perth but other places have them too). When I made my table (smaller than yours, a coffee table really) I had a bar clamp ever 500m along the length. These clamps pull the boards together both horizontally and vertically - worked a treat for me! (Don't forget to put some plastic between the bars and the top, like I nearly did, or they will stick to your table really well:doh:)

You will need to make the actual bars themselves from some strong timber rather than pine (I used 40mm jarrah) but the clamps come with blurb to show how.

Best of luck

[m2c1Iw]

ps I'm almost positive they have not warped or twisted since planing. They come out of the root of a 50 year old house.

OK now I'm confused are they twisted as the pics suggest or not and are the edges square. The piece you have clamped across seems to show cupping and out of square edges and sighting down the length there appears to be twist as well. What is the assembly resting on and are there cauls underneath to hold everthing flat.

[Wongdai]

Thanks guys,

You're going to have to keep this simple, as I am new at this wood working stuff, and don't sometimes get what you mean.

m2c1Iw: I don't think the timber is twisted, but there is at least one piece that bows from end to end. So not cupped on the width but on the length. Shouldn't a planer have removed this discrepancy?

The assembly is resting on my table saw. I don't know what cauls are sorry. I could move them to another table that I know is flat if you think that will help. I will do that tomorrow night.

Swifty: How much were these bar clamps you talk about?

Ron: I don't think the board is twisted. I think the it is out of square, so when I pull the clamps up it skews up.

Wongdai

[DJ’s Timber]

It looks and sounds like they haven't been jointed square.

[artme]

To me it looks like you have 2 problems:
#1-Boards have been thicknessed in a wedge shape across the width.
#2- Not properly jointed.

[Wongdai]

OK, recovering from my depression of yesterday, I have been out for another look today. It looks like you are all correct - with some of the lengths the sides are not square to the top, and there is at least one where it looks like the width of the board is a wedge shape.

I tried pulling them all together mechanically, but the differences are too great to be accommodated.

Some are better than others however, and I have lots of lengths, so I am going to go back with my trusty Marples try square and see if I can find the best pieces.

My FiL is going to give me his jointer/planer one day, so hopefully I won't have this problem again in the future.

[Wongdai]

OK, almost none of the edges are square to the top.

Is it possible I could straighten these up on my router table? Is there such a thing as a 42mm deep router bit that I could just run the boards up against?

[m2c1Iw]

OK, almost none of the edges are square to the top.

Is it possible I could straighten these up on my router table? Is there such a thing as a 42mm deep router bit that I could just run the boards up against?

Yes but that assumes your faces are indeed flat. Did you assist with the jointing I ask only to enquire how it was done. The procedure is to surface one face then after checking that the jointers fence is at 90deg an edge is then run with the freshly jointed face against the fence. Next thickness to the desired final dimension plus a smidge to allow for smoothing. When all that is done the width can be done on a table saw or as I sometimes do is run the board jointed edge down through the thicknesser.
Guess what I'm saying is it might be quick and easier to start again on the jointer.

Hope that helps

Cheers
Mike

[Swifty]

Wongdai, I used an electric hand planer to square up my edges before putting the biscuits in. You will need a right angle guide (usually supplied) and you can get it pretty straight eyeballing it in lengthwise, and using square to test edge squareness. Did this on one edge then ripped it on a table saw to make the other edge parallel, then lightly planed ripped edge.
Hope that helps. I've seen several other posts in the General Woodworking forum that deal with making straight edges, some really clever ways to do it (better than mine I think).

[Wongdai]

Thanks Mike

Yes, I was there for the jointing, but not the thicknessing. He seemed to know what he was doing, but there was no checking for square. My assumption was that it would just come out square (somehow).

Unfortunately my FiL is in hospital now, so I might be simpler and quicker if I just go buy myself a 42mm sraight edge router bit. Alternatively I could ring him up and ask to borrow his jointer/thicknesser, but it is a heavy beast and I don't think I would be able to get it into the trailer myself.

Additionally, I'm not clued up on using and setting up jointers.

Actually, I might go run a could of edges through my dodgy table saw and see how they come out.

edit: Thanks Swifty - I don't have that attachment for my electric planer unfortunately.

[weisyboy]

i use my router table to joint boards only up to 25mm thick.

you can use a table saw to joint boards i have some pics here some ware i think.

or a good hand plane and a keen eye.

[Wongdai]

Hoi! The table saw works a treat! I'm very happy as I have not used my table saw before.

Mind you, when I cut the first one the table saw tipped up as all the weight went to the rear, but I have some sandbags holding it down now. :p

Thanks for everyone's help, but stay installed for the next exciting episode of "When Things Go Wrong".

[m2c1Iw]

:2tsup: more pics, we want to check your work :roll: :D

[artme]

Mind you, when I cut the first one the table saw tipped up as all the weight went to the rear, but I have some sandbags holding it down now..

Methinks you need some roller stands. El cheapos from Bunnies will do.

[Wongdai]

:2tsup: more pics, we want to check your work :roll: :D

Will do, just as soon as I finish putting this lot through my TS.

Roller stands hey? That sounds like an idea. I assume some sort of height adjustable thing that sits out the back of the TS. Can't say I've ever seen anything like that at Bunnings though.

Is there anything I can spray on the surface of my TS to make the timber slip through a bit easier? I'm old and weak and its getting tiring pushing these boards through! :C

[Swifty]

a little bit of wax on the surface may help

[artme]

Your supposition is correct Wongdai. Bunnies have had them on special from time to time.They will save you no end of trouble.
I have 2 and sometimes use one either side of the table.

Clean ttable to a shine with ROS or elbow grease. Coat with Carnauba wax or you can buy Silverglide from Carba-Tec.

DO NOT use anything with silicone.

[Wongdai]

Hi all

After a whole bunch of false starts, and quite a bit of time with my No 6, I have the butts joining fairly smoothly now. Some of the boards are bowed and so I will either attack the glued up top with a floor sander or make up a jig for my router and plane it that way.

These pics are from a practice clamp-up.

http://i111.photobucket.com/albums/n123/wongdai/wood/IMG_2043.jpg

As you can see the top needs some planing...

http://i111.photobucket.com/albums/n123/wongdai/wood/IMG_2044.jpg

[weisyboy]

looks good now:2tsup:

[artme]

Now that's more like it! :2tsup::2tsup::2tsup:

[Expat]

One word of caution....... put some wax paper between the pipe and the glue lines.

[simon d]

Another tip. See those pieces of wood you've got under the boards. Put another piece on top in the same way (beam ways) and clamp the two together from each side of the top to keep the whole assembly from bowing up into a cup as you tighten the cross ways pipe clamps. You should put a set of clamped timbers beam ways, at both ends and in the middle and then tighten your pipe clamps in opposite tensions. By that I mean put a pipe clamp under the table top and then the next one over the table top and so on and try and use four at least. I'd use six for a top that big. That way the tension in the clamps is equalized and doesn't pull the boards out of square. After it's all tight place a piece of waste along the edge and give it all a good whack with a mallet next to the clamps and then tighten again.

[Wongdai]

Ahhh. Good advice, but it is now glued, and it is ever so slightly bowed.

I'm going to take to it with a floor sander tomorrow and flatten it out, so no dramas, but definitely good advice for next time I do a table.

[Expat]

I forgot to mention alternating top and bottom with the cross clamps. That helps to even out the pressure and you can use the pipes to force the boards flat and square.

[simon d]

Oh dear. I've done it myself once and the problem is that the glue join is much thinner in the cup than it is on the bottom, presuming the cupped side is your top face. Did you use biscuits or a tongue and whip join between the boards? If not you might find the boards separate soon after you've fixed it to the frame, because the unequal glue regime can't cope with the natural expansion and contraction of the wood. If you did you'll find they take a little longer to separate. Glued joins can expand and contract with the wood but only if they are even in their thickness and pressure at the time of application. If not they'll expand quickly at the thin high pressure side and very slowly at the thick low pressure side, unequal expansion equals spilt join starting at the top first.
In this case you have to replace the join with an additional one or break the top down and start again.
One hidden remedy to minimise the splitting is to cut with your router, a series of 15mm wide and 20mm deep diagonal dovetail trenches right across the underside of your top in a large cross hatch pattern. Then slot in dovetailed whips that fit snugly but not too snugly as you won't be able to get glue in them. One direction is all long ones which you screw in place at the centre of each board and the other direction is made up of short whips that run between the long ones and also screwed in place at the centre of each board.
What they'll do is use their resistance to shearing forces to reduce the spreading of the boards once the glue in your butt joins breaks.
Another remedy is to bolt every board down to a series of cross rails on the underside of your table using sunken coachbolts. These rails are then checked into your bench frame.
Both remedies mean you'll have to level the underside as well as the top. The break down version is to knock the joins apart, clean off the glue and resquare the sides and clamp again using the equalized pressure technique.
good luck with it and mind you, I'm a masochist!

[Wongdai]

I did use bisciuts between all the boards, so I'm hoping the problem won't be too bad. I did notice some gaps between the boards appearing today, as we were using the floor sander outside in the sun. I'm assuming the sun was changing the moisture level in the boards and causing them to contract. The gaps aren't too bad, but they are still somewhat disappointing. We got most of the cupping out with the floor sander. The whole top now feels nice and smooth.

I've given both sides a coat of poly now to prevent any further moisture changes.