Planning to make new window sills from MDF for the living room.
One of the sills will be somewhere around 250-260cm and about 20cm deep. From what I've seen, MDF only comes in 244cm. The thickness is likely to be around 30-35mm - initially, I was thinking of cutting a windowsill in, say, 16-18mm and then screwing/gluing a piece underneath to make it look more solid.
Now that the MDF needs to be joined along the length, the entire windowsill will become 2x the board thickness, which in itself isn't an issue - the question is how to join the MDF most neatly and relatively easily? I lack biscuits or a router, but I have a bunch of good quick clamps.
Do you think it will work well if I take a 150cm and 100cm piece and screw/glue them together with a 100cm and 150cm underneath - with an offset joint?
Looking forward to opinions and advice.
One of the sills will be somewhere around 250-260cm and about 20cm deep. From what I've seen, MDF only comes in 244cm. The thickness is likely to be around 30-35mm - initially, I was thinking of cutting a windowsill in, say, 16-18mm and then screwing/gluing a piece underneath to make it look more solid.
Now that the MDF needs to be joined along the length, the entire windowsill will become 2x the board thickness, which in itself isn't an issue - the question is how to join the MDF most neatly and relatively easily? I lack biscuits or a router, but I have a bunch of good quick clamps.
Do you think it will work well if I take a 150cm and 100cm piece and screw/glue them together with a 100cm and 150cm underneath - with an offset joint?
Looking forward to opinions and advice.
It will surely be excellent to do as you plan, and I wouldn't bother with screws. Wood glue and clamps are sufficient for the intended use. For the length you are talking about, you likely have a number of brackets?
As for the appearance, I assume you are going to paint the window sills – if you fill carefully, the joint should not be visible.
Good luck!
Ronnie
As for the appearance, I assume you are going to paint the window sills – if you fill carefully, the joint should not be visible.
Good luck!
Ronnie
The first window I crafted here at home (actually the first window ever) was precisely a slightly wider section where 2440mm was not enough. Foolishly, I patched it with a slightly angled joint + glue and a piece underneath. I don't know why I thought it would work, a makeshift solution doomed to fail. So this is something I need to redo, and I thought I'd take the router and mill a tongue and groove + place a piece underneath. What I need to patch is about 15cm.
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Even though MDF is perceived as a dead material, it is, however, made of wood. This means it moves throughout the year depending on moisture content. It might be possible to biscuit join it, but otherwise, I claim that it is doomed to fail to splice it without being visible.
As mentioned here earlier, it is available in longer lengths. It can be a bit difficult to obtain as a private individual though. Not all retailers have it. But on the other hand, it should be possible to order a sheet.
As mentioned here earlier, it is available in longer lengths. It can be a bit difficult to obtain as a private individual though. Not all retailers have it. But on the other hand, it should be possible to order a sheet.
Thanks for the advice MathiasS
Your window woodwork (surely it's yours I've seen pictures of) forms the basis for my ideas! I don't own a router at the moment, but what better reason than this to get one.
Guzzi
I'll check with AB KarlHedin, they're good and should be able to get it if joining is not an option.
Your window woodwork (surely it's yours I've seen pictures of) forms the basis for my ideas!
I don't own a router at the moment, but what better reason than this to get one.Guzzi
I'll check with AB KarlHedin, they're good and should be able to get it if joining is not an option.
There are surely many good ways to solve this and likely many of them are better than mine from a general sustainability perspective. But the question is whether we are chasing the optimal or if good enough is OK?
As I read Fredrik's suggestion, it involves two layers of MDF (layer one 100 + 150 cm and layer two 150 + 100 cm) with well-offset seams – that’s a lot of surface to spread glue on. With strategically placed support points, I find it hard to believe it won't hold.
Additionally, biscuit joining can be a good excuse to get a hand router, of course... You have to seize every opportunity.
Best regards,
Ronnie
As I read Fredrik's suggestion, it involves two layers of MDF (layer one 100 + 150 cm and layer two 150 + 100 cm) with well-offset seams – that’s a lot of surface to spread glue on. With strategically placed support points, I find it hard to believe it won't hold.
Additionally, biscuit joining can be a good excuse to get a hand router, of course... You have to seize every opportunity.
Best regards,
Ronnie
Ronnie, I've tried roughly what you're describing and concluded that it doesn't work. The paint cracks and it's not "good enough".
With tongue and groove and plenty of glue, however, I think it works; it creates a very strong joint.
What do these extra-long boards usually cost? Double the price?
With tongue and groove and plenty of glue, however, I think it works; it creates a very strong joint.
What do these extra-long boards usually cost? Double the price?
Sheets in the size 3050 can be ordered from the nearest lumber yard, it takes a week or two. MDF moves, my longest casing around a window is 7000mm and sure, you can see the joint now and then, and it was glued with adhesive all the way against the frame.
As a windowsill, you can glue a thin laminate layer over the MDF if you have made seams, and then you will definitely not see any seams. It can also be overnailed if desired. This works especially well if you have many plants in the windows where water spills and pot marks otherwise leave marks. I get my laminate from a carpentry shop.