Hi all
I have made a cover for some box work out of MDF and tiled the top. Unfortunately it looks like the adhesive action has caused the cover to bow. Guess I should have applied weights to hold it flat while the adhesive went off :(. If I weight the cover is such a way to reverse the bowing, will this reverse the process, or will it just re-bow in time?
TIA from a newbie wood-worker
Phil
Do you mean ceramic tiles, Phil?
If so, ply is likely to be a better substrate
If the cover is not going along the sides of the boxwork ie not resting on the top of them? it will bow with the weight of the tiles and will not flatten out. If the cover is thin? it still will not flatten out for the weight of the tiles, will bow it.
On Tue, 31 Jul 2007 10:13:20 GMT, "George" mused:
Sounds like it has bowed in the opposite direction to which you think it has.
"George" wrote
Sorry fellas
Yet another poor explanation of the situation! The cover forms the top of the boxwork and sits flat (horizontal) - approx dimensions 700 x 210 and is supported underneath all four edges. It is made from 12 thick MDF with a 20 x 9 frame on top around ceramic wall tiles. Tiles stuck in place with Bal White Star. I had laid the cover in position for the adhesive to dry, but the ends have "curled up". I have now turned the cover upside down, supported each end and sat a box of photographs on the "back" to try to straighten it. I didn't use ply as the edge of the board is visible.
Phil
You could drill through the tiles and bung some mirror screws in. Best to wait a couple of days for the adhesive to dry completely. I must say I've never had this problem with 12mm mdf
Hi,
Is there framing attached to the MDF itself? This should minimise bowing, but it needs to be much thicker than 9mm.
It sounds like you tiled straight onto bare MDF which may have caused the surface under the tiles to swell and then shrink.
cheers, Pete.
"Pete C" wrote
Only cosmetic framing around the outside of the tiled area
Yes I did tile straight on, but have found that applying PVA to MDF or ply results in a similar bowing effect. There is still the grouting operation to contend with - might make matters even worse :-( I was hoping to have a simple lift-off top for the boxing to gain access to the toilet cistern below. Otherwise the chrome top screws would have been an option. I have fitted a plastic lid of sorts to the cistern to prevent moisture hitting the underside of the cover (even though the cover is painted underneath).
Phil
If some 1" or bigger planed batten is clamped and glued underneath it might straighten it out. It shouldn't need to be right up to /on to the edge either.
Maybe putting PVA on both sides would minimise the effect. Or better still use a sealer that isn't water based.
cheers, Pete.
"Pete C" wrote
Yes I had considered additional webs, but the cover is heavy enough as it is! I can see SWMBO trying to lift it off and dropping it/smashing the loo seat :-(. Guess I'll give it a day or two with the weights on and see if it holds shape
Thanks
Phil
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.