Thread: Advice Please. What mistakes am I about to make?

I have not been able to view your attachment.

Some silly questions. Is the property rented or owned? Is the desk going from wall to wall?
If the desk is going from wall to wall, and you are allowed, you could build a frame attached to the walls and only have one supporting leg on the front in the middle.

Pine frame and Tassie Ash top is OK, if the frame is visible just stain the visible part to match.

Everything is possible, it just takes time and money.

Please post WIP images.

the 45mm vic ash tabletop will easily span 1500mm between legs with little to no sagging. if you needed to climb up on top of it to change your network cables, just put your weight near the legs, but the top will support you anyways.

if you dont like the look of the blond pine against the brown/red vic ash top, you could always paint the frame any colour you like (except mission brown) and it will look good.

you can reasonably expect to lose 10mm off the width of the boards during jointing, it quite easy to lose even more than that with a 3meter length. i recommend getting 2@240x45 and 1@290x45 or get roughsawn timbers if you can at ~250x50.

using such wide boards, there is a substantial chance that the boards will cup over time leaving a wavy surface. this may or may not be appealing to you. using thinner boards such as 90x45 (~100x50) will create a long term stable and flat top, especially if the boards are all quartersawn.

a tall bedside set of drawers at each end.
A double width one for the middle.
and then just lay the top on those.

I had this in my room with my brother as a kid, gave us 2 desks and no construction.
Plenty of draw space on each side and the middle was for all the extra stuff.

Greetings again.

Thanks for the responses thus far.

Answering questions asked above.


We own the place, so we can build it in wall to wall.

My concern was that by actually going 'wall to wall' and building it in, I'd have to get the desk top EXACTLY right. Where as the 'free standing' desk would allow me a 10cm margin for error. (and for the room to be out of square)

Having typed that, I've spent the last 10 minutes dreaming of ways to go about your suggestion.
oh well, yet another design. The boss is going to love this. "Have you given up on the desk?" she's asking.


Mission Brown wasn't going to be an option. I once spent what seemed like forever as a kid painting our back fence pailings Mission bloody Brown. I still don't enjoy painting to this day and as for "mission brown".... I believe the forum rules forbid my expressing my true opinion.

I guess I will get/use the thinner boards and go for the long term stable flat top.

Thanks for the idea fly. Having been stuck in the public service for the last 30 yrs, one of my goals with this project is to actually plan something, get it done and being proud of the end result. So I will be building the lot.... one way or the other.

Once again, thanks for the input guys.

Cheers,
Tob.

Hi Tobster,

I recently did something like that in same sized room. Mine is very utilitarian but is a very useful addition.

One side is the girls' sewing area, one side is my office. The drawers are cut from one of the desks that used to be there. Timbers on wall and front edge are 90mm x 35mm pine. Top is yellow tongue floor sheet which I chose because one piece is long enough to go from wall to wall. I could stand on this no problem, and your top with 45mm thick timber would be stronger again, I would guess.

I threw in a photo to show the wall gap. Yes the walls are out of square and the back edge wall is bowed as well. I'm going to put some beading to tidy it up. No really, I am You really need to leave a bit of a gap anyway to wrestle the top into place without scraping the walls.

One thing you could do to save a bit of money is make the top out of 20mm thick timber and just make the front edge 40mm thick. To get the 40mm thickness at the front you can laminate two 20mm thick pieces together.

This is a desk I made about 13 years ago that might give you some ideas

It's 2.3m long on on the LHS, 1.8m on the RHS and 3.3 m across the back
The top is solid Jarrah slab 42 mm thick, L and R side tops are 780 wide the back is 850 mm wide.
The top pieces are not fixed to the supporting pieces of furniture underneath and just sit on top of some pieces of grippy plastic - the weight of the tops means they do not move around.
The gap in the top you can see across the middle of back is a removable 19mm board about 70 mm wide with notches cut in the sides and are where power and computer cables can pass up through from the cupboards underneath. this works really well.

More details here https://www.woodworkforums.com/f40/computer-desk-28521
If you don't build it in I recommend attaching a small raised strip of wood to the very back of top to reduce the amount of stuff that falls off the back.

I would also suggest something harder like Ash over pine for the top as pine also gets beat up too easily

If you want to remove the middle leg altogether and minimise stretcher intrusion underneath the desk you can use a length of steel angle partially embedded underneath the top.
You would need something like 50 x 50 x 6 mm angle. Routing a groove 50 mm wide by 6 mm deep will leave 44 mm of angle which is half the width of a 90 mm wooden stretcher and you can hide the metal with a thin wooden strip. You might even be able to get away with 40 x 40 angle.
My desk has a unsupported edge ~1.7m long along the front of the back of the U that is supported by a 25x25x5 mm piece of angle.

Wow.

Thanks a lot guys.
I was awake until 2am last night thinking about how I could incorporate/manage some of the ideas already thrown up... and worrying about some of the questions they posed.

The last couple of posts have answered pretty much all of my 'new' questions and really opened up my options.

Expanding wood had me worried about making the desktop go wall to wall.
so I love the idea of the desk top being a tad short to allow for expansion, and using some trim to
a) Hide the gap
b) Stop stuff from falling off the back and/or edges.

I'm even more happy about knowing that the weight of the desktop will be enough where I won't have to try and attach it. (or figure out HOW to attach it)

And it's taken me [20 minutes] 40 minutes an hour 2 hours to type this post, because I keep getting lost inside my head thinking about options and alternatives.


... I **THINK** I have come up with an idea that may work - is the following feasible?

Goal #1 : Use 50x50x6 angle iron to support the entire desktop across the front.
Goal #2 : To accomplish goal #1 'invisibly'.

Uneducated theory....
Assumption #1. The strength of the angle iron relies on it's angular construction, not in it's actual alignment.

If Assumption #1 is correct
Maths says that if the angle iron happened to be inverted so it rests on both of it's edges, with the 'angle' at the top, the relative "height" of the angle iron would be 36mm or so.

Assumption #2. Hypothetically, If someone was to cut out a vee into the bottom of the table top that just happened to be ohhhh... 36mm deep, then aforementioned angle iron could be positioned into slot where it would subsequently provide a) all the necessary support while b) remaining invisible to the naked eye. (Naked eyes bove desk top height anyway.)


QUESTION. Would two 40x40x5mm pieces be as strong as one 50x50x6mm? Given that I'll be using 50x100 pieces to make the desktop, I could just as easily repeat the process and have 2 support bars.
(off to google to get that answer..)
[there went an hour of my life looking at engineering formulas... Turns out form 6 physics from 30 years ago just doesn't prepare you for those engineering websites. My brain hurts.
The simple solution... call an engineer relative. Unfortunately I have to wait until Tuesday when he's back at work to get the answer.

anyway, in order to cater for a couple of other particular requirements I'm going to have to go with a bit of both solutions.
It has at least given me a name for the project. "Tobsters Fantastic Flying T Desk."
(euphoria in effect due to all problems being solved)
Now all I need is the ability to get what's inside my head out onto paper and then into wood.

Thanks muchly all.

cheers
Tob

Please don't take my word that 50 x 50 x 6 will be totally fail safe and please seek other advice.
My rough and ready method is to go to the steel merchant and place a length of steel of interest a few cm off the ground and stand on it and see how much it flexes. Even when I reckon its OK I usually buy the next size up to be sure. If it's possibly life and death I go 2 or even 3 sizes up. This method works with square tube and flat bar but is very hard to do with angle or round tube. as it wants to tip over or roll so it needs to be clamped.

[QUOTE=Tobster;1849140
Uneducated theory....
Assumption #1. The strength of the angle iron relies on it's angular construction, not in it's actual alignment.[/QUOTE]
Nope

If Assumption #1 is correct
Maths says that if the angle iron happened to be inverted so it rests on both of it's edges, with the 'angle' at the top, the relative "height" of the angle iron would be 36mm or so.

That's it weakest configuration
You absolutely will need to have one side vertical - to do what you want to do you will need something like maybe 65 x 65 x 8 mm angle but then that kinda defeats the purpose?

QUESTION. Would two 40x40x5mm pieces be as strong as one 50x50x6mm? Given that I'll be using 50x100 pieces to make the desktop, I could just as easily repeat the process and have 2 support bars. b

Yes you could do that but then you might as well use SHS (Square hollow tube). This is a perfectly good thing to do, another reason being it can be obtained in a good smooth finish.
If you use SHS you can go for a lighter gauge e.g. 50 x 50 x 3 would probably work (see first statement above)

Let me confuse you a little more. There is another way that involves using all thread rod that is put through a hole down the middle of the wood and put under tension - like a guitar neck - but like I said that is tricky (but not impossible) to do.

Greetings again.

Thanks BobL, I managed to read your post JUST as guests arrived, so I've been a slightly distracted host for the last few hours thinking about what you said.

So... now I've had time to read it carefully.

Don't you hate it when assumptions do what assumptions do. Talk about one of those "Really???!!!???" moments.
What a Bummer. I thought I was onto a winner with my clever manipulation of the angle iron.

Fortunately I won't be needing it to work at 100% efficiency.
BUT... would it be viable as an insurance policy do you think?

My thoughts/plans BEFORE your post included a bit of both options. A center leg & the angle iron.
(albeit the angle iron inverted).

The only solution I could come up with to support the lower shelf and the small upper shelf, was to utilize a center leg.
Obviously the center leg is going to add support to the actual table top - thus assisting the angle iron.

I've added v2 of my table design - (Bonus. On the second day of sketchup, I discovered the color palete.)
V2 even addresses power cord access, a method of reducing the power cord hole size and also provided a trim to hide the wall gap and to stop things falling off the ends/edges.

Anyway, back to the plan.
Keeping in mind that my 'hidden' angle iron isn't/won't be as effective as it could be, I figure that it'll still provide SOME support. Which means I will now need to center leg to now take on more of the work. Ergo...
Initial thoughts were to have the legs all 50x100, but I can just as easily laminate them all to bring bring them up to 100mm sq.
(all material to be the Tas Oak seeing as I'm only doing the one 'set' of legs its not that much more material.

Thoughts on how effective that would be? Would 50x100mm be enough? Would 100x100 be enough? Would the angle iron even be necessary?

Once again, thanks for the input & advice.

cheers,
tob
ps, I recon I'll sleep better tonight.

If you use a centre leg the angle iron is unnecessary.

The leg should match the size including thichness of the top
A 50 x 100 leg would be fine - maybe even better? but bear in mind that this a non-standard wood size.
A more standard size would be 90 x 45, which would also be OK
It's more work but the leg could even be tapered to give it a less clunky appearance.
Something like tapering it down from 45 at the top to 35 mm at the floor level.

Posting designs as anything other than a jpeg will limit the feedback from members.
I don't know that many people on this forum that use rafting program to begin with and even those that do are unlikely to want to fire a up a program to look at something.
If you embed the images direct into the text that makes it much quicker for folks to follow.

Greetings.

Thanks again.
Feels like I've finally gotten the design solid enough to start working on measurements etc.


No probs re jpg's. (Another assumption on my part from earlier browsing of the forums was that attaching Sketchup files seemed to be the preferred method.)

Cheers,
tob