So I've bought 4 pieces of 1x0.5m 18mm thick MDF and I'd like to join them to form a tabletop
#mdf tabletop
ornate lantern
glossy helm
Throwing this in from general.
The challenge you've got is "Jointing", which you can look up on youtube. You need to make sure the edges are square and dead flat, then you can glue them together, and so long as you brace them underneath , you'll be OK.
ornate lantern
Alright
glossy helm
Do you have either a router, table saw, or long hand plane ?
ornate lantern
What would you suggest for the braces?
glossy helm
Anything rigid
ornate lantern
I'm going to be working on the at my friend's house who has builders working on his house
glossy helm
Could be C channel, could be a 30x20 bit of timber, etc.
ornate lantern
👍
glossy helm
Well if you want to joint two panels you need a level of flat & square that most builders will be unfamiliar with.
If you really want to joint them
Like, get them invisibly flush
(Which is what wooderworks mean when they say jointed panels)
This will illustrate it.
ornate lantern
I don't think it has to be invisibly flush as I will have white vinyl on top
ornate lantern
Hang on
Should I get plywood boards instead
My friend didn't buy the boards since it was dodgy
ornate lantern
@glossy helm sorry for the ping but what do you think?
glossy helm
You'll replace one set of problems with a different set of problems
Esp. @ 12mm
Like MDF, plywood is not born equal.
ornate lantern
What would you suggest?
glossy helm
The reason I haven't is because I can't.
golden idol
You could use dowels to try to help with alignment of panels too... If you're going to be covering it with vinyl/laminate you don't care about pretty, you just need flat and smooth. If after dowling you still have a seam you can sand it or fill it or both.
I agree with Denyerec that you're almost certainly going to want something stiffening it up.
glossy helm
Should I just buy like an IKEA tabletop and cut it
Often these aren't solid.
You COULD
But you'd need to make sure whatever you were cutting was something whose edge you were happy with
(Hey Felix!)
glossy helm
I'm not sure that last set of dimensions makes sense
ornate lantern
whoops
ornate lantern
But would it be better?
glossy helm
Fewer joints is usually better because there's fewer opporunities to cock up
In my experience, anyway 😄
glossy helm
I don't think I can steer you adequately there.
Personally decent MDF is a lot cheaper than decent plywood.
ornate lantern
Would decent msf suffice in holding around 20kg?
glossy helm
My desktop is 18mm MDF on an identical frame to yours
it's been fine for a decade
Yes, you want to brace it, especially given the design of your table frame.
ornate lantern
How much weight roughly is on ur desk?
glossy helm
"A bunch"
glossy helm
two monitors, arms, two monitor speakers, my fat arms.
ornate lantern
Wow,all that on 18mm mdf??
ornate lantern
Damn I think I've underestimated mdf severely
ornate lantern
Check sagulator and be surprised
Will do
ornate lantern
What is 0.002 cr?
That's what I got for 25kg load centered on 12mm thick mdf
Wow
That's amazing
ornate lantern
You mean timber?
I probably will buy some wood beams to brace it with
Does the brace have to connect to the frame or can the brace just be connected the the underside of the 2 tabletop pieces?
Will it break if most of the weight (20kg) is concentrated on the seam in the middle?
If I don't add braces
glossy helm
Ok, stop and think about it mechanically.
If you glue some thin wood panels together
Then stand in the middle of them
What do you expect happens next?
The crossbar will support some of that, but the leading and rear edges are essentially unsupported
I would not want to commit to yes/no over the internet
I woudln't trust it without a brace though,
Personally.
So from a sample of One Random Dude On The Internet, no.
ornate lantern
Could be C channel, could be a 30x20 bit of timber, etc.
@glossy helm do you mean mm or cm
glossy helm
If it's a single peice of 18mm I an tell you from my own experience, no.
A single sheet of 12mm... Sagulator
Cost wise if you don't go to B&Q and go to an actual MDF supplier they can probably custom cut a single sheet from 8x4ft stock for less money in better quality.
Where are you based
ornate lantern
The frame is arriving today so I'll test it
ornate lantern
What glue would I use to stick 2 pieces on marine mdf together?
ornate lantern
i'll try to borrow some g clamps from my schl
do i have to somehow seal the mdf b4 i stick white countertop vinyl onto it?
glossy helm
Test it
Given that MDF can be a little dusty, it might be necessary, but the moisture resistant stuff is pretty hard
Fuzzy
Not dusty
If you don't get good adhesion, then shellac probably the quickest and easiest thing to do
Sometimes sold as sanding sealer, but please ask in the finishing channel about that as I may be wrong
ornate lantern
ok
golden idol
Whenever you are using shellac as an undercoat you need to make sure it is dewaxed.
glossy helm
He's using as a base for vinyl - would that still apply?
I suspect sending sealer will be the correct thing to use here, but would appreciate some backup 😄
glossy helm
I don't know anything about that product I'm afraid.
The specific product is called sanding sealer
Looks like somebody routed you a couple of pork chop joint cuts with a worktop template?
ornate lantern
I brought it to school and my teacher used a jigsaw and a flat piece of wood as a template to cut it
I marked it out before hand
The mdf bowed a bit so the lines aren't the straightest but I'll just sand that
What are pork chop joint cuts?
ornate lantern
https://www.toolstation.com/natural-pale-shellac-sanding-sealer/p94067
How would I apply this?
glossy helm
It's a jig like that, you basically use it to make the funky shaped cut line but you use a router so the edges are perfectly perpendicular
glossy helm
Careful sanding you don't want to round the edges. If you're going to send an edge wrap the sandpaper around a wooden block and do everything you can to keep it perpendicular
glossy helm
My teacher just clamped a plank of wood on 🙏
That's all most of the jigs are
That was just the first Google result
You can get cheap ones that are just basically white-faced plywood
ornate lantern
Careful sanding you don't want to round the edges. If you're going to send an ed...
👍
glossy helm
Apply the sanding sealer with a disposable brush
ornate lantern
You can get cheap ones that are just basically white-faced plywood
Oh alright
glossy helm
Shellac is basically bug shit dissolved in alcohol
When the alcohol evaporates the shellac solidifies
You can then dissolve it later with more alcohol if you want
ornate lantern
So if you hairdryer it, it will dry quicker?
glossy helm
You can apply it to glass, it is one finish that will literally stick to anything
ornate lantern
You can apply it to glass, it is one finish that will literally stick to anythin...
Yippy
glossy helm
You won't need to, it dissolved in high concentration alcohol that will have evaporated by the time you find the hair dryer
Again read the instructions
ornate lantern
Kk will do
glossy helm
Did you test the vinyl adhesion to the bear MDF
ornate lantern
No, I should do that.i watched a video online that just said that mdf was too dusty when it wasn't sealed but the mdf I have isn't really dusty
glossy helm
What you think is dusty and what somebody describes a surfaces dusty are two different things
It's not a layer of dust sat ck on it
It's the fact that particles of MDF tend to detatch from the surface
Because all MDF is, is dust and glue
ornate lantern
Ahh that makes sense
glossy helm
A bit like skin in a way, bits are always falling off
You should be able to notice that the green MDF feels harder
That's because it's produced slightly differently to attempt to keep water out, so tends to be a bit higher density with a bit more glue, basically
Should you ever wish to paint MDF, make sure you get MDF primer, specifically.
It just works a whole lot better
Also after the first coat of sanding sealer the surface might feel rough, use some 220 or 180 grit to lightly get rid of the rough texture
glossy helm
Do you have a squeegee for your vinyl application
If not, head to YouTube and watch a few videos
If you get bubbles in the top surface they're going to drive you mad
ornate lantern
Ahh ok
Does b and q sell squeegees
Nvm I'll google it
Would this work,pretty sure I have one at home
ornate lantern
Quick question would a 250ml bottle of sanding sealer cover 1x2m
glossy helm
Quick question would a 250ml bottle of sanding sealer cover 1x2m
Read the bottle. I'm going to suspect yes.
For dry vinyl application you usually want something like a felt squeegie, hard but soft.
You could use a ruler with a microfibre cloth tight around it, for example.
You need to apply firm pressure but not drag the vinyl, car applicators are usually felt edged bits of plastic.
Halfords might have em
_might)
TEST IT FIRST
TEST TEST TEST
Test your finish on scrap, or be prepared to scrap your entire finish.
ornate lantern
ah ok
ornate lantern
Hi, so the table frame provided screws for the tabletop
However they are just a tad bit too long
So to counter this would I just put like rubber bands between the washer and wood?
Or just more washers
glossy helm
MOre washers would be preferable.
Or buy shorter screws.
Rubber bands will compress and degrade over time.
ornate lantern
Ah ok
ornate lantern
So I have a question, the bottom panels (to cover the inside of the table) will be made of cardboard. How would I make that cardboard white and smooth as I think putting vinyl onto it will make it wrinkly
Also the tabletop holds the weight nicely without being screwed to the frame
ornate lantern
@glossy helm
glossy helm
Oh that's looking tidy chap!!
OK cardboard is a bit wanky as a structural material when it's a single sheet as it is very reactive to moisture.
If you can find a stocking (Sign makers, double glazing guys etc) then white coroplast is much better.
It's the kinda corrugated cardboard that's actually plastic. and the little tubes are squares rather than wavy corrugations.
That'll stay flat if you put vinyl on the face, but you can also buy it in different colours.
Don't forget to pull the vinyl tight round the edges of your table whilst using a hairdryer to get the wrinkles out.
ornate lantern
Ya 👍
ornate lantern
OK, I resorted to cardboard with vinyl on top as I was in a crunch for time.
glossy helm
If the card curls you can glue on some wooden bracing, like long thin bits of wood too keep it rigid
ornate lantern
Yh I glued on some dowels
ornate lantern
glossy helm
Nice!!
What's the software there, is it a a CFD aerodynamics sim for the car body model ?
ornate lantern
Ah no, it's just a game we made in ue5
But the cfd software we use for the car is ansys fluent
glossy helm
Sweet!