Sapele front door threshold: really tough clear finish?

[Eric the Viking]

At least, I think it's Sapele - Mahogany colour, with obvious salt crystals (they catch the light in the workshop), but not as dense and tough as Teak. It seems much easier to work than Teak, too. It needs some protection from muddy walking boots, etc., and it's far too pretty for paint. I can coat it before it's fitted, mostly (there will be drilled and plugged fixing screwholes though). It doesn't really get direct sunlight, but obviously it is exposed to the outdoors (we have a good porch roof but without side walls).

I'm thinking possibly a 2-part poly marine varnish, but that stuff tends to be incredibly expensive, and doesn't seem to keep well either (so a lot of waste). Possibly a Rustin's product (maybe "Clear Plastic Floor Coating"), as they're good and easily available from Toolstation...?

If no actual recommendations, is there anything to specifically avoid?

 

[Phil Pascoe]

I used to use R.P. floor coating on dance floors - excellent stuff. Use throw away brushes, they aren't worth the time and thinners needed to clean them out.

 

[PAC1]

1. Yacht varnish.
I have also found Ronseal Diamond Hard floor varnish to do what it says on the tin. I varnished my workshop floor with it 20+ years ago. No wear whatsoever.

 

[Malc2098]

Could it help to grain fill with epoxy resin like I do with my instruments, then any finish can go over the top, even more epoxy, perhaps.

 

[Eric the Viking]

Could it help to grain fill with epoxy resin like I do with my instruments, then any finish can go over the top, even more epoxy, perhaps.

That might work, although it's pretty close-grained already and smooth off the planer (yes, I will sand it through the grits).

It's a bit of reclaimed timber (thanks Rafe-Z!), and it's beautiful, but it's pretty dry, so does have a propensity to tearout and splintering/chipping. The grain is also very pretty, but rippled.

I have my almost-finished top surface now, and I'm cautiously thicknessing it underneath to size, where tearout won't show if it happens (no. 4 1/2 from here on in, probably). It has to be a wedge, lengthwise along the door, so the thicknesser can only get me so far, and it's a 4ft wide door.

Router table for roundovers this morning, with a brand new cutter to get the cleanest finish, then sanding. I bought 11mm and 12.7mm roundovers, so I can 'hog out' most of it to 11mm radius, then have a couple of thin passes to roughly 1/2" finished.

 

[Doug]

I was recommended Sikkens Cetol WF960 by a friend who makes windows when I needed to put a finish on a sapele (?) bench my mother in law had bought, https://www.sikkens-wood-coatings.com/exterior/details/cetol-wf-960
Two years on it’s still looking good.

 

[Phil Pascoe]

I don't know Sikkens would handle the wear of a threshhold.
I got a good finish on some really wild grained sapele by cross planing with a very, very sharp iron then going straight to sanding. Works for elm, as well.

 

[Mike G]

Could it help to grain fill with epoxy resin like I do with my instruments, then any finish can go over the top, even more epoxy, perhaps.

Whilst that would work, and work well, my understanding is that epoxy isn't UV-resistant, and so it would need a varnish or lacquer over the top. Personally, I reckon this is likely to be the most durable option for a threshold.

 

[Malc2098]

Whilst that would work, and work well, my understanding is that epoxy isn't UV-resistant, and so it would need a varnish or lacquer over the top. Personally, I reckon this is likely to be the most durable option for a threshold.

Although it's not the type that I use, I believe there are UV resistant systems that are used for yachts and surfboards.

(If i were a surfer, I'd be a fair weather surfer and only surf in the sun. )

 

[AndyT]

These products - Owatrol Deck Oil - are made for protecting decks on sailing boats.

Decking Oil | Decking Treatment - Owatrol Direct

Our decking oil range includes single coat finishes, anti-slip finishes and wet-on-wet application finishes, as with Owatrol, there is always a solution.

www.owatroldirect.co.uk

I don't own a teak-decked luxury yacht (so I have no experience of its effectiveness ) but I do have a little sample of Deks Olje you could play with, if you like. It's a very thin oil which penetrates deeply and dries clear, with no effect on the colour. Easy to apply.

 

[Eric the Viking]

Thanks everyone. Given the urgency, and the use model (the DC brings muddy boots in via that door, etc.), anda certain nervousness regarding oil finishes, I've gone for the Ronseal "Diamond Hard floor varnish". I think it's a standard polyurethane (albeit with driers added), and although it's an exterior door, it's out of the weather.

It has to be finished by Tuesday, at least to the level that it's properly in place, so (stupidly) I've made a rod for my own back.

I couldn't find a local supplier for Rustin's two-part floor varnish: Toolstation only stock a selection from Rustin's range, and anyway enough for 10m^2 was somewhat excessive.

Thanks, Andy for the info above, too.

I've had mixed success in the past with marine products. I used to sail a lot, back in the days when everything "needed" polyurethane. I always used International one-part (everyone I knew did), but it took several decades to harden enough to sand back, and was fine until water got under it, at which point it became both useless and horrid to remove. Skarsten scrapers anyone?

I tried International 2-part (from the chandler in Bristol Docks, at a huge price), and couldn't get it to set - the chemistry was either faulty or it was old stock and expired. Either way it was a horrid problem thereafter, and a very expensive one, both money and time fixing it afterwards.

I have no idea what this varnish will be like, but I do get to do several coats on the bench before I have to fit it in situ, so we'll see.

One advantage of it being on the bench is that at least I can degrease it properly, and cover the surface underneath as well. This both protects and helps with warping/splitting. It'll be screwed down to the concrete, so the plugs will have to be finished as patches to the coating. I hope it doesn't look too horrid as a consequence.

Still not confident I've done the right thing, but at least I've made a decision.

 

[toolsntat]

Thanks everyone. Given the urgency, and the use model (the DC brings muddy boots in via that door, etc.), anda certain nervousness regarding oil finishes, I've gone for the Ronseal "Diamond Hard floor varnish". I think it's a standard polyurethane (albeit with driers added), and although it's an exterior door, it's out of the weather.

It has to be finished by Tuesday, at least to the level that it's properly in place, so (stupidly) I've made a rod for my own back.

I couldn't find a local supplier for Rustin's two-part floor varnish: Toolstation only stock a selection from Rustin's range, and anyway enough for 10m^2 was somewhat excessive.

Thanks, Andy for the info above, too.

I've had mixed success in the past with marine products. I used to sail a lot, back in the days when everything "needed" polyurethane. I always used International one-part (everyone I knew did), but it took several decades to harden enough to sand back, and was fine until water got under it, at which point it became both useless and horrid to remove. Skarsten scrapers anyone?

I tried International 2-part (from the chandler in Bristol Docks, at a huge price), and couldn't get it to set - the chemistry was either faulty or it was old stock and expired. Either way it was a horrid problem thereafter, and a very expensive one, both money and time fixing it afterwards.

I have no idea what this varnish will be like, but I do get to do several coats on the bench before I have to fit it in situ, so we'll see.

One advantage of it being on the bench is that at least I can degrease it properly, and cover the surface underneath as well. This both protects and helps with warping/splitting. It'll be screwed down to the concrete, so the plugs will have to be finished as patches to the coating. I hope it doesn't look too horrid as a consequence.

Still not confident I've done the right thing, but at least I've made a decision.

With regard to fixing it down I have taken to using PU glue particularly on internal thresholds.
You might have nothing to lose and all to gain if you did the same in this instance.
If, in the future, you need to resort to a screwed fixing it's still a feasible option.
Cheers, Andy

 

[Eric the Viking]

Thanks Andy, It's going to be a bit tricky...

We have a huge & lovely old softwood door. Someone took a saw to the bottom of it, very roughly, so it's approx. horizontal for about 400mm, hinge end, then dives upwards, to finish (around 1200mm width altogether) about 10mm higher at the lock side. They broke into the stile mortice for the haunched tenon on one side.

Then there's the floor level, which is now about 28mm higher than the original (unavoidable). The door opens across a mat well that's about 1200 square, and it's on massive rising butts, which are a get-out-of jail-free card - they lift it so that it won't be trapped by the carpet going down later next week. My threshold strip forms the fourth side of the mat well.

Rafe and I re-hung it a few weeks back, so it's now correct in the opening, and my measurements are from that. I checked the fit earlier today, after a lot of planing, and the threshold is still too thick. I'm resorting to a belt sander shortly. My intention is to hollow it out a bit underneath with a 'surface trim' cutter and add a couple of grooves either side for caulk to squeeze into:


That's a horribly-drawn cross section, and a bit out of proportion (it'll be flatter than shown).

The actual thing will be less than 2" tall, by a varying amount (to roughly follow the door damage) There will be at least one brush strip bearing on the top surface - inside ansd probably outside also. I'm aiming to plant the door roughly centrally (it's about 2" thick). I would emphasize this is a least-worst option, any chance of a proper threshold with a stop are non existent, because of (a) the historical attack on the door with a toothed, bladed weapon, and (b) subsidence that has required the removal of the floor and a new level to be established. If I did go for a normal threshold, I'd end up with something about 3" up off the front step, which is unacceptable as a trip hazard.

I have to screw the strip down from the outset (counterbored and plugged), because I'm relying on screws to pull it down onto a slightly dished floor. The 1/2" radius roundovers couldn't be cut with the stock to its final shape.

So I'll have caulk, but not glue.

Hope that makes sense (and sounds reasonable!).

E.

 

[Jonathan]

Eric, I run a window and door company and we now use pu/polymer for all external chalking. The one we use doesn't sink like silicone or caulking, its waterproof, like caulking it take paint, and above all it acts like an extra fixing.
Regarding your choice of finish for threshold, I would also use a water-based finish due to ease of use and ease of re aplication in the future.

 

[duke]

What is pu/polymer, is there a marketing name for this?

 

[Jonathan]

Duke, basically its a polymer based sealent.
The first one I started using was https://www.ct1.com/our-products/
Now most silicon manufacturers are producing it