Flattening scaffold board desk

[ACElexus]

Good morning,

I have a desk that is made from three scaffolding boards biscuit jointed together.

Whilst it looks lovely and despite being sanded by the supplier, the desk isn’t completely flat, rising and falling around the grain and knots. This isn’t ideal for some of the computer mice sensors I use for precision work.

I have tried to sand where it’s obviously proud using a spirit level to see the highs and lows, but it’s still not great.

Spoiler: Desk

To finesse the final parts that are still a bit much for my mouse to track over, I imagine that I kind of want to run a massive pencil lead over the surface so that it only marks the areas still proud. Obviously that massive pencil lead doesn’t exist at 40cm in length. I’ve thought about putting a bit of wood oil on the bottom of the metal spirit level and ‘wiping’ it across the area to mark the parts that are proud, but I suspect there’s better ideas. Any suggestions? I can do it bit by bit, by hand through a fabric mouse mat but it’s imperfect and wonder if there’s a better way.

I’ve used a random orbital sander to do most of the work to this point but will probably finish with a sanding block by hand, 80 – 120 – 240 grit.

Thanks in advance.

 

[RandomGrinch]

Alternatively, as it seems to be only the mouse use that's the main issue, have you tried something like a hard surface mouse pad?

https://www.amazon.co.uk/Logitech-Optimised-Friction-Non-Slip-Accessories-Black/dp/B07W7LNTMC/ref=mp_s_a_1_3

 

[Why Not Indeed]

A drum sander is probably the "proper" tool for this but it's presumably not something you have hanging around.
I would consider something known to be flat - a thick sheet of glass, for example - and carefully glue some sheets of sandpaper to it, then use that as your "sanding block". Suction handle on the back to manipulate it with.
If ultimate flatness is the goal then whole timber is probably not the right material as it will shrink and expand at different rates with changes in the environment. So get a mouse mat.

 

[Tigercubrider]

You can buy a powder in a “puff” intended to replicate a mist coat for car bodywork. However it could stain the boards (?)
That would highlight high spots and low spots if you insist on a sander.

The best way would probably involve a router sled.
This is a track on supports that bridges the desktop. A router with a reasonably wide cutter is gently moved side to side ad across the surface, milling all the high spots as it’s gradually lowered to meet the low spots.

A decent chippy could do it for you, cheaper than buying a router and making the sled.

 

[freddiemercurystwin]

There's a video that YouTuber Rag 'n' Bone Brown did on flattening a scaffold table top, think he used a power plane to get it flat in the first instance (though I recall he wasn't after a perfect finish anyway) but if you search through his videos it will show what's what.

Or just buy a mouse mat as suggested.

 

[ACElexus]

Alternatively, as it seems to be only the mouse use that's the main issue, have you tried something like a hard surface mouse pad?

https://www.amazon.co.uk/Logitech-Optimised-Friction-Non-Slip-Accessories-Black/dp/B07W7LNTMC/ref=mp_s_a_1_3

Thanks. This was my first thought, to workaround the problem. Initially, the grain and knots were so variable that the hard mouse mat rocked. In the same way my keyboard (feet) do! I then remembered why I don't like hard mouse pads and have ditched them previously, not enough friction because they're all designed to be low friction for PC gamers.

A drum sander is probably the "proper" tool for this but it's presumably not something you have hanging around.
I would consider something known to be flat - a thick sheet of glass, for example - and carefully glue some sheets of sandpaper to it, then use that as your "sanding block". Suction handle on the back to manipulate it with.
If ultimate flatness is the goal then whole timber is probably not the right material as it will shrink and expand at different rates with changes in the environment. So get a mouse mat.

No drum sander unfortunately. Good suggestion; I’ll have a look in the loft to see if I can find something solid with a large flat surface area to try this.

You can buy a powder in a “puff” intended to replicate a mist coat for car bodywork. However it could stain the boards (?)
That would highlight high spots and low spots if you insist on a sander.

The best way would probably involve a router sled.
This is a track on supports that bridges the desktop. A router with a reasonably wide cutter is gently moved side to side ad across the surface, milling all the high spots as it’s gradually lowered to meet the low spots.

A decent chippy could do it for you, cheaper than buying a router and making the sled.

Thanks for your suggestion. Getting a chippy in to do this is more money than I have to spend at this stage.

There's a video that YouTuber Rag 'n' Bone Brown did on flattening a scaffold table top, think he used a power plane to get it flat in the first instance (though I recall he wasn't after a perfect finish anyway) but if you search through his videos it will show what's what.

Or just buy a mouse mat as suggested.

I did think when I was first sanding down that a planer would probably be better suited to the job but I didn’t have one. I might have a look if any of the local tool rental places have one. I’m keen to ‘fix’ the problem as best I can rather than workarounds, but understand fixing may be prohibitive on an available time/cost basis.

Another idea I’ve had which I’m going to try is getting a 1mm thick of sheet aluminium and screwing it into the boards over the affected area. Hopefully it will have enough rigidity to remove the ridges from a 4mm cloth mouse pad on top of it. Feels like a good trade-off time/cost/outcome compared to fixing.

Thanks all

 

[foxhole]

Needs 40/60 grit to level before finishing .
Or simply use a kitchen cutting mat under mouse mat with foam feet for rock free operation .

 

[Tigercubrider]

In order to make a sacrificial tool for a job, I bought a black and decker used electric plane on eBay for less than £20 inc P&P
You could buy something, use it and sell it on?

Electric planes are scary, only hold the top and use it adjusted to the lowest setting to get used to it

 

[RandomGrinch]

I'm just wondering if a flat, mouse mat shaped indent, can be routed out of the table, with a basic template?

 

[ACElexus]

In order to make a sacrificial tool for a job, I bought a black and decker used electric plane on eBay for less than £20 inc P&P
You could buy something, use it and sell it on?

Electric planes are scary, only hold the top and use it adjusted to the lowest setting to get used to it

Thanks for the suggestion, I might look at a second-hand one from a marketplace. If not for this job, for future.

I'm just wondering if a flat, mouse mat shaped indent, can be routed out of the table, with a basic template?

This sounds like a nice idea but I don't have a router. Moreover, it would make the mouse mat semi-permanent and if I chose to move from the left of the desk to the middle (220cm from wall to wall) at some point in the future, I couldn't just 'lift and shift'.