Finishing oily woods

[Muina]

I'm building a bedside cabinet with an Iroko frame (I'm gonna post a buildalong when I'm finished), but I'm trying to think of the best way to finish the whole piece.

The drawer fronts will be Ash and the panelling Tulip Poplar so I want a nice glossy finish. But I'm wondering, will Danish oil hold on the Iroko? It is a type of "turnip Teak" as they say, so it's extremely oily.

My thoughts are to leave the wood in the sun for a day or two to bring the oils up to the surface and keep wiping it down with nail polish remover/acetone, what do you think?

Thanks

Anthony

 

[MIGNAL]

Oily woods retard the drying of any oil varnish/finish. It is common to put a barrier coat (something like Shellac) straight onto the wood. You can then apply another type of finish on top. Danish oil is not really a gloss type of finish, unless you apply LOTS of coats and rub down/buff. I haven't tried it but I've heard that Liberon finishing oil can be built to a gloss finish as well.
Golden rule: try your finish on an off cut of the wood first.

 

[Muina]

I have finished a wood called Ipe (don't know if it's well known, it's called Brazilian Walnut, it's a bit like Teak and Iroko but even harder and even heavier) with Danish Oil on a Longbow before but I didn't bother waiting more than an hour for each coat to dry before applying the next and after 6 coats it was really glossy so I've done that with everything I've finished with Danish Oil since and they've all been quite nice finishes. Anyway, that did work quite well but Ipe's not quite as oily as Iroko.

I'll try the shellac thing, I've got some friction polish for turning, do you think that'll work?

Anthony

 

[mbartlett99]

Can't speak as to Iroko but if its anything like teak which I deal a lot with its shouldn't be a problem. Teak doesn't require any special treatment although occasionally we do get some salesman swearing blind that some degree of witchcraft is required. Bear in mind that most of your finishes are oil based anyway.

Want a bit of gloss - three coats of Epifanes varnish, dead easy, bit of protection from the elements, can vary the level of gloss as required.

 

[Muina]

Well I've been told that Iroko is a "turnip" Teak which means it's basically kind of a cross bred Teak to produce a small branch off from the "pure" species, so I'm pretty sure it'd finish just like Teak. Thank you for the info!

But just a thought, I know that Timber treatment companies use a technique called empty cell preservation which is when they dry the timber out beyond equilibrium moisture content, and then because the timber wants to equalise the moisture they put a preservative on the timber and it draws it deep into it's cells.

I know this doesn't sound relevant, but give me a bit of time to explain my thoughts... What I'm trying to say is that the way this works is kind of like finishing a piece of wood, the wood soaks in the oils and then they dry, but if the oils are already there, i.e. Iroko, would this not compromise the quality of the finish?

Thanks again

Anthony

 

[Erasmus]

Iroko is really nasty, gives off a choking dust when machining or sanding and leaves me wheezing for a week after one day in the workshop with it. Far as I'm concerned it belongs in the garden as a bench or planter or some other such like outside construction where left unfinished it weathers down quite nicely. I have had to use it under client pressure for kitchen worktops on occasion and liberon finishing oil does produce a result if you don't slap too much on at a time. I remember one lady who put so much oil on her Iroko worktop that it resembled treacle. I had to remove it and refinish for her. If you want something that looks like Teak, use Teak.

 

[Muina]

Thanks, I'll have a look for anything like Liberon Finishing Oil in my garage.

The only reason I'm using it is because when I went to my timber merchants, they have a section of reject hardwoods, and there was a huge board of Iroko 8' x 2" x 10" for just over £10. The workable parts were the perfect size for what I wanted and I've used Iroko before so I know how beautiful it can be (that's just been proven when I planed it up!).

I know Iroko likes to move and stay oily but the contrast between the Iroko visible frame and the Ash drawer fronts will look amazing I think

P.S. I know what you mean about the dust, it's actually a carcinogenic believe it or not, I remembered that just as I realised how much dust there was kicking about in my workshop just from cutting it on the bandsaw, and that was with dust extraction on! I literally couldn't see the other end of the room and it's not a big garage at all lol

Anthony

 

[Erasmus]

Pleased to make your acquaintance Anthony.

I worked for a company in the '80s specialising in garden furniture (gazebos, Pergolas, trellis, benches, planters etc) using Iroko which they used to paint as well as natural finish. We used to build for the Chelsea flower show each year. It was always problematic to finish, paint particularly. Kiln dried tends to move quite dramatically when working. Probably okay in the sort of section sizes you're dealing with though. Moisture content is important. If you want to be really fussy, 'settle' it slightly oversize in the environment it will end up 'living' in for 6 weeks or so. Assuming little or no movement has occurred, finish size it then settle it again. I do this with any material until 'proven' stable and I also reject and replace rogue pieces. My career in fine furniture has always demanded this. I'm a bit of a perfectionist, so shoot me lol.

We used to avoid kiln dried in preference to air dried stock because of the 'outside' application. Can't fault it in terms of 'fit for purpose'/ attractiveness where garden use is concerned though. The honey coloured boards are better than the darker ones and avoid that swirly grain wherever you can (not easy). Make sure you protect yourself against the dust, most hardwoods are carcinogenic to my understanding but Iroko is in a league of it's own. The inside of my car and clothes were permanently yellowed lol. I would certainly use a cabinet scraper for fine finishing.

I'm sorry to throw up so many negatives in respect of Iroko but it's better to fully understand the properties of your chosen material in my opinion. I'm sure that with all things considered and a degree of patience, you'll achieve a lovely result. The contrast you speak of will look good, no doubt. It will be nice to see a photo when you've finished, good luck with all.

 

[Muina]

Thanks for the information

I do the same with all pieces I'll be using, I'll take them into the room they finished product will be in (if I'm making it for myself) for at least 2 weeks to help it move as much as it will before I start on the piece, I also try to time the builds in the transition from winter - spring or summer - autumn so you get the differential movements in the cold and warm weather.

I also make sure to season any kiln dried wood in quite a moist environment (the bomb shelter at the bottom of our garden keeps the moist air quite well) and when I feel it's ready I'll "re-season" the wood as if I was air drying from scratch. I think this way I'm letting the wood do what it wants to instead of trying to control it, which is when the balance is disturbed and it'll try and gain back control if you get what I mean (I know I've gone all Hippie but it kinda makes sense )

Anthony