Ipe table top question

[fobos8]

Hi guys

I have a few leftover lengths of Ipe decking and I'd like to make a table top from them for an outside table. The Ipe is 21mm thick and in 140mm wide pieces.

I've attached a rough sketch. My plan is to rip the pieces down to make them approx 70mm wide. I'll then make a frame shown in grey in the sketch. I plan to fix slats to the top of the table shown in blue in the sketch. I'll fix the slats in place by using 40mm washerhead screws fixed through the frame into the underside of the slats. Screws shown in red.

The frame with be joined using Festool dominos and glue.

My only real concern is whether the slats will stay in place with only about 18mm of screw holding them in place?

Any thoughts from people who have done something similar.

Cheers, Andrew

 

[recipio]

You would probably get away with it for a while but seasonal movement would gradually loosen the slats. The general rule is to screw a mobile component to a fixed so you should screw from the top if possible. Stainless steel screws are a good idea and you could hide them with wooden plugs. With respect it's not the most elegant design . As you have a domino machine could you not join the endgrain of the slats to the outer rails dispensing with the middle rail.?

 

[fobos8]

You would probably get away with it for a while but seasonal movement would gradually loosen the slats. The general rule is to screw a mobile component to a fixed so you should screw from the top if possible. Stainless steel screws are a good idea and you could hide them with wooden plugs. With respect it's not the most elegant design . As you have a domino machine could you not join the endgrain of the slats to the outer rails dispensing with the middle rail.

thanks recipio. Your right. I was thinking of knocking something together quickly, but I do want it to last a long time.

I've seen pics of quite of lots of Ipe furniture designed like this

 

[fobos8]

If I domino the slats into the frame of the table what would be a good width for the slats. Can I go as wide as 43mm?

Cheers, Andrew

 

[recipio]

If I domino the slats into the frame of the table what would be a good width for the slats. Can I go as wide as 43mm?

Cheers, Andrew

It's entirely an aesthetic choice. The only problem is the danger of cupping of the boards so if you go beyond about 70 mm it would be better to use two dominos if possible. In general the narrower the slats the more elegant the piece will be - but that means more work of course. Never used Ipe - I believe it is a very hard wood.

 

[peter-harrison]

I don't agree that you shouldn't screw into the ipe. My principle is if you have the choice, screw through thinner/softer into thicker/harder. Ipe is definitely hard! AKA ironwood and well named.
Joining the slats to the frame using dominoes sounds like a lot of hassle for no benefit. the main force on a tabletop is upwards- either from cupping or from lifting the table- and this is the weakest direction for a domino joint especially one that's kept outside.

 

[Fitzroy]

Whichever solution you go for leave a good distance between the slats. I made a table with 3mm gaps on 100mm slates and they all closed up over the seasons. The top now holds water and needs some rework.

F.

 

[fobos8]

Thanks for your advice. I've decided to screw. I'm desperate to make something quickly, the family is getting sick of eating outside off a sheet of plywood.

It won't win any design awards but I'm not too fussed.

I have Ipe outside as decking. Its still looks amazing after 8 years. It has moved a bit and some of the screws have lifted a few mm but the screws are into softwood joists so I think its to be expected.

 

[Fitzroy]

I’d you could orient the boards with the heart side downwards you could use an insert nut in each board centre then a machine screw through the frame to the insert nut.

Any cupping would be towards the frame so should be resisted. I think an insert nut/machine screw would resist the effects of weather better than a simple screw.

Fitz.