Thread: Australian Hardwood vanity unit questions

It's probably a bit late now, but, for a wet area, polyurethane is better than PVA as it's 100% waterproof, even exterior PVA is only water resistant.

If you want some extra security, you can screw 40x40x3mm L-section steel inside each corner (with elongated holes to allow for movement). Definitely do NOT glue ply to the inside; it can cause it to cup severely.

Originally Posted by elanjacobs

It's probably a bit late now, but, for a wet area, polyurethane is better than PVA as it's 100% waterproof, even exterior PVA is only water resistant.

Yeah, hindsight. It will be coated with resin or 2 pack (satin), including all the predrilled holes, so moisture ingress should be minimal.

Originally Posted by elanjacobs

If you want some extra security, you can screw 40x40x3mm L-section steel inside each corner (with elongated holes to allow for movement).

Would oversize holes (9mm) for 4-5mm diameter screws with flat heads be sufficient, or do I need more room than that?

Originally Posted by elanjacobs

Definitely do NOT glue ply to the inside; it can cause it to cup severely.

Great, thanks for that info.

I think that hole size will be fine; lots of small laminations are generally more stable than large pieces, so there shouldn't be much movement.

elanjacobs,
Thanks for your assistance above.

Here are some images of the project:
Clamped (with a twist unfortunately - bent the table top that it was clamped to as it set):
s_20161016_175633.jpg
Routed (to remove twist):
s_20161029_164708.jpg
Glued and internal steel brackets fitted (I am happy with the waterfall end as I only lost 1.5mm in the cut):
s_20161113_102525.jpg
Clear finished (the internals are now black - used bituminous body deadener):
s_20161115_155144.jpg
Third coat (the grain would have looked better if I stopped at two coats - see my review of the clear finish here: Intergrain Ultrafloor Pro
s_20161115_155120x.jpg
Done.
s_20161224_101349.jpg

Lovely vanity. Is that an Alape Unisono basin? I need to redo my bathrooms and I was looking at 2 of the Unisonos for the en suite and an Alape Metaphor for the main bathroom. I was also thinking of a white or grey cabinet with a Vic Ash or Spotted Gum top... but your mitered vanity looks so good I'm having second thoughts.

Did you use any mechanical fasteners for the back plywood to the laminated body or just rebate and glue?

Edit: Sent a picture to the wife, she says 'Looks awesome, very swish'.

Looks great. Well done SPF

Hi Alkahestic, thanks for the feedback.

Originally Posted by Alkahestic

Is that an Alape Unisono basin?

No its an Eden from Highgrove: Eden Bench Mount Basin Matte White | Highgrove Bathrooms

Originally Posted by Alkahestic

I need to redo my bathrooms and I was looking at 2 of the Unisonos for the en suite and an Alape Metaphor for the main bathroom. I was also thinking of a white or grey cabinet with a Vic Ash or Spotted Gum top... but your mitered vanity looks so good I'm having second thoughts.

We bought two of those basins because we are doing an en suite too, and it doesn't look too big in either room. I made this cabinet on a whim because I was at a timber yard and they had the strips sitting there at a good price, and my wife loved the grain. If I was doing it again, here are the top 10 tips in hindsight:
1. Make sure you use clamps that can clamp the strips together, and keep the panel straight in all directions. Taking out the twist with the router and sled was an unwelcome distraction.
2. Use polyurethane glue.
3. If you use planks or anything else with a round or chamfer on it, cut this off before you start and work with nice square edges and freshly cut glue faces.
4. If using steel brackets for supports inside, make sure that the thickness of the panels is the same across the depth of the panel (mine weren't due to the twist and routered top). I did this because I wanted to, but realised during the glue up, that if I hadn't I would have been in trouble.
5. If using Australian hardwood with highly contrasted grain, it is probably going to warp due to the difference in the moisture content. You may have to break the grain to get it to work. I did this with 3 of the strips in the vanity. I pre clamped the timber as I would for gluing it and let it sit for two days with the fan blowing over the top. The pieces that failed, sheared along the border of the two different colours in the grain, so I unclamped them, and then made sure I added glue in the shear line and vacuumed it through the gap before clamping up the panel.
6. I'd seriously look at using epoxy as the base coat of the cabinet if doing it again. Then you can add an automotive/marine polyurethane over that.
7. Consider adding a drain hole in the bottom of the cabinet, so you know if there is a leak in your pipes/sink. The plumber didn't fit the s-bend properly, so the sink was leaking into the cabinet, and because it has a lip at the front it filled up to the lip before we realised.
8. Leave enough room (height) in the strips for the French cleat for your builder to have a couple of goes at getting it level, or use fasteners with flat heads so that you have some wiggle room to allow for leveling when the holes in the wall are drilled in the wrong spot. Or better still don't use a french cleat if you can find a better way to mount the cabinet.
9. Give your plumber as much room as possible for positioning the pipework, but tell them they have a lot less.
10. One of my motivations for building the cabinet was to avoid the cheap feel of the drawers that come in commercial units. I used heavy drawer runners, but the drawer still isn't nice to use (better than what I could buy, but not great). So I would make sure that you make the drawer body first, fill it with stuff and test some runner systems. I'll probably end up making something to replace the runners. The best commercial option I have found is the Blum bottom mount drawer runners for kitchen drawers, but $$$$$$$$$$$.

Originally Posted by Alkahestic

Did you use any mechanical fasteners for the back plywood to the laminated body or just rebate and glue?

Yes, I used mechanical fasteners - the ply is not rebated into the hardwood as I did a load test with a rebate and the hardwood splits really easily along the grain. It only took 300N of force, or just over 30kg to split a full length piece that had been rebated and the ply glued into it. So the ply is framed in at the back with 18mm wide strips of ply that are glued with poly and fixed in place with screws. This also provides the setback for the French cleat that holds the vanity to the wall, so that the vanity sits up against the tiles when in place.

In addition to that, as suggested by elanjacobs, there are 25mm angle steel supports in each corner to prevent total destruction in the case that the glued joints fail, and because of where the studs are in the wall, I also added a strip of steel in the center of the top panel so that any creep in the glue over time (or deformation of the ply and french cleat) would be minimised, and contained in the case of total failure. This strip is then bent at 90 degrees the end and hooked over the top edge of the ply, to give a mechanical interference - even if all the laminated panels fail, this will prevent the vanity coming off the ply back.

There is a stitching screw in each piece of the lamination that goes through an oversize hole in each of the pieces of steel. The theory being that the timber can swell and shrink a little without cupping or tearing the lamination apart. To help with this, the steel is painted with xylene based galv primer which isn't lubricative, but it fails in shear, so will allow the screws to slide under load.

I also did a load test for this vanity to see what force the cleat would be exposed to, so I could use suitable fasteners. With the vanity supported at the bottom and blocks preventing it sliding backwards I pulled the unit from the cleat using a fish scale and measured the load that it took to lift the front edge off the supports (with the basin and some weights in place to allow for the drawer and some contents). All told there was 37kg of vanity unit and fixtures, and the load on the scale was between 58 and 60kg. This isn't a perfect way to test all the loads, but it did confirm my calculations, and gave me some comfort about the vanity not tearing out of the wall if a tradesman (or a child) decided to climb up on the vanity to do something (which appears to be a very common reason for failure).

I hope that helps.

Thank you very much for taking the time to do such an in depth explanation, much appreciated. I'll be finished with painting most the house interior this weekend, then I have to give the bathrooms much needed thought. I had a look at the vanities on display at Reece and I have to agree with you, the drawers and doors feel very flimsy, and I'm sure none of them can take the load you've designed your vanity for. Considering the very large price tags, it's pretty disappointing.

Alkahestic, for the price the stuff at Reece is disappointing I totally agree. Unfortunately, the quality doesn't get much better anywhere else until you start spending obscene amounts of money. I didn't have a table saw and a few other things before I started but worked out that I could buy them, make the vanity and a couple of other pieces of furniture and save about $15k on the furniture and fixtures on the reno. Of course for the purposes of the reno my time is free.