Process for refinishing teak chairs?

[davidjames]

Hey,

I have acquired a couple of teak armchairs that need refinishing. All the joints are strong and we like the design/shape.

They must be at least 20 years old or so, and are marked quite badly in parts.

I am confident in stripping the old finish, sanding back. But I have not restored teak before and my research hasn't came up with much - should I "feed" the wood with something before applying a varnish? What is the best finish to put on something like this?

Thanks for your thoughts.

[Big Shed]

No need to "feed" the wood with anything.

Furniture of that vintage was probably (spray) finished with a pre-cat lacquer, usually of reduced gloss level.

Mirrotone would have been one of the suppliers.

Any good professional paint store would be able to supply you with this, they should have a sample board from which you can pick the required gloss level.

[Xanthorrhoeas]

Hi David,

If you are able to attach some photos you may get some more replies.

Here in Australia teak is often left to go grey outside, but if kept inside it could be finished in many different ways. I have some teak that had been oil finished and that can be refreshed without sanding by just adding more oil - as long as it hasn't gone grey as if that has happened the oil makes it go black and it has to be sanded back. There are also products containing Oxalic Acid that will remove most or all of the grey from timber (one here in Aus is sold as "Dekswood" but you can also buy oxalic acid on eBay and make your own for less money).

I also have some teak that seems to have been finished with what looks like polyurethane - though this may be the pre-catalysed lacquer mentioned by Big Shed - I am not familiar with that product as I do not spray finish anything. The teak oil or a marine finish applied over the top of mine seems to work OK on that too.

Regards

David

[Xanthorrhoeas]

PS I have also seen teak furniture that has been French Polished (i.e. with shellac) and that is easy to test for - just rub an inconspicuous spot with metho - which will remove French polish. If it is that it is easy to apply more shellac to refresh the finish.

[davidjames]

Hi David,

If you are able to attach some photos you may get some more replies.

Here in Australia teak is often left to go grey outside, but if kept inside it could be finished in many different ways. I have some teak that had been oil finished and that can be refreshed without sanding by just adding more oil - as long as it hasn't gone grey as if that has happened the oil makes it go black and it has to be sanded back. There are also products containing Oxalic Acid that will remove most or all of the grey from timber (one here in Aus is sold as "Dekswood" but you can also buy oxalic acid on eBay and make your own for less money).

I also have some teak that seems to have been finished with what looks like polyurethane - though this may be the pre-catalysed lacquer mentioned by Big Shed - I am not familiar with that product as I do not spray finish anything. The teak oil or a marine finish applied over the top of mine seems to work OK on that too.

Regards

David

It's in our tiny flat at the moment so not easy to photograph, but I have this older one below.

It's an indoor armchair, so has not greyed (like oak will as well outdoors without treatment).

I need to emphasize these are *very* rough in places and will need to be sanded, filled, and have a couple of joints re-glued and clamped.

There are *black* lines in places, which I assumed were just old splits that had got filled with gunk, but there are lines in odd places where there is no split as well, so I'm not sure what they are.

These chairs definitely have a upper finish on them, although it's worn through to the wood in many places. I will have to test for what it is as suggested.

I am planning on applying a matte varnish in order to make it hard wearing and protect them for another good few years.

I guess I was wondering initially if I needed to treat the wood with anything else before the varnish/lacquer etc, but it seems not from what you guys have said.

BTW, these obviously weren't expensive! I am going to refinish them, and re-upholster them, and I think they'll be great then. They're actually very comfortable as they are (but a bit disgusting...)

View image: $ 57$_57.JPG

[Xanthorrhoeas]

Hello again David,

I suspect that Big Shed was correct and these chairs (known here as Danish or Scandinavian design) were most probably spray finished with a lacquer. As I said, I know nothing about such spray finishes but perhaps he can enlighten us as to whether they can be stripped easily using a solvent or whether they need to be chemically stripped (paint stripper) or sanded back.

If you want to completely remove the old finish it is important to realise that chairs are time-consuming to sand because of all the tight corners at the joints, though, in the positive, teak does sand well and comes up looking like new timber if you can sand - or scrape thoroughly into those spots.

I can't see the black that you mentioned so do not really know what you would need to do about it (if anything).

So, basically, I am not much use to you here if you do want to completely strip them. Perhaps someone else will be able to advise you.

My son and daughter-in law do have some very similar armchairs that need a clean back and some repair work (as well as a reupholster as the fabric is much worse than yours). I am not planning to strip them completely though, but rather just to sand the knocks and dents (very lightly so as not to get the "new teak" look) then seal those patches with some shellac before applying some wax to all the timber work to buff them up. That may be an alternative for you if you do not want to spend a lot of time. I have had success with the technique on other furniture and it keeps the age and patina of the furniture. Old furniture does decrease in value once it loses its patina and these "retro" pieces are now becoming quite valuable so that is a factor worth thinking about.

If you do need to re-glue some joints it would be good to check whether the original adhesive was a hide glue. If it was then it will soften with very hot water (protect nearby finish with masking tape before applying the hot water from a kettle). The best glue to use in that case is a new hide glue as other adhesives will not bond well with remnant hide glue in the joints. An easy way to use hide glue is Titebond liquid hide glue. Otherwise you need a glue pot and "pearl glue - hide glue, which may be difficult for you to source and use if you are not familiar with it. Sometimes just reviving the old hide glue with hot water then reclamping the joint will work but it is safer to add some new glue as well

[Big Shed]

First of all, my apologies, didn't realise you are in the UK, so my mention of manufacturers names would be of no use to you.

However this sort of mass produced furniture was almost exclusively finished with a fast drying clear finish, almost exclusively a lacquer due to the demands of quick drying in a factory environment.

This could have been a straight nitrocellulose, a cab-acrylic (unlikely, relatively expensive) or a catalysed lacquer (either pre or post added). Of these, pre-catalysed lacquers were the most common.

To find out what is on those chairs:

If the finish can be relatively easily removed by rubbing wit lacquer thinners - it is nc

If not it is either a cab-acrylic or catalysed (pre or post) if so then either mechanical removal (ie sanding) or chemical removal (ie paint stripper)

If the finish isn't in too bad a condition you could of course just rub back and recoat, either with one of the above mentioned (spray) lacquers, or a polyurethane varnish. I wouldn't recommend a matt varnish though, especially not on chairs, as they gloss up from constant rubbing, ie on the arms etc. A satin would be preferable.

[davidjames]

My son and daughter-in law do have some very similar armchairs that need a clean back and some repair work (as well as a reupholster as the fabric is much worse than yours). I am not planning to strip them completely though, but rather just to sand the knocks and dents (very lightly so as not to get the "new teak" look) then seal those patches with some shellac before applying some wax to all the timber work to buff them up. That may be an alternative for you if you do not want to spend a lot of time. I have had success with the technique on other furniture and it keeps the age and patina of the furniture. Old furniture does decrease in value once it loses its patina and these "retro" pieces are now becoming quite valuable so that is a factor worth thinking about.

If you do need to re-glue some joints it would be good to check whether the original adhesive was a hide glue. If it was then it will soften with very hot water (protect nearby finish with masking tape before applying the hot water from a kettle). The best glue to use in that case is a new hide glue as other adhesives will not bond well with remnant hide glue in the joints. An easy way to use hide glue is Titebond liquid hide glue. Otherwise you need a glue pot and "pearl glue - hide glue, which may be difficult for you to source and use if you are not familiar with it. Sometimes just reviving the old hide glue with hot water then reclamping the joint will work but it is safer to add some new glue as well

All very helpful sir, thank you for this.

I quite like a project from time to time and this is just that, I realise it'll be quite a bit of work involved, but nothing particularly complicated, so I'm happy to go ahead. Once I've got the finish off /sanded I'll inspect the joints and see if they react to hot water. I was planning on just syringing some in there and clamping but this is very useful to know, as I don't even have hide glue to hand yet.

[davidjames]

First of all, my apologies, didn't realise you are in the UK, so my mention of manufacturers names would be of no use to you.

However this sort of mass produced furniture was almost exclusively finished with a fast drying clear finish, almost exclusively a lacquer due to the demands of quick drying in a factory environment.

This could have been a straight nitrocellulose, a cab-acrylic (unlikely, relatively expensive) or a catalysed lacquer (either pre or post added). Of these, pre-catalysed lacquers were the most common.

To find out what is on those chairs:

If the finish can be relatively easily removed by rubbing wit lacquer thinners - it is nc

If not it is either a cab-acrylic or catalysed (pre or post) if so then either mechanical removal (ie sanding) or chemical removal (ie paint stripper)

If the finish isn't in too bad a condition you could of course just rub back and recoat, either with one of the above mentioned (spray) lacquers, or a polyurethane varnish. I wouldn't recommend a matt varnish though, especially not on chairs, as they gloss up from constant rubbing, ie on the arms etc. A satin would be preferable.

Thank you for thinking about that, I will proceed to have a go with some lacquer thinner to begin and see where that gets me.

Noted on using a non matte varnish as well. I imagine spraying would be easier for something of this nature (many sides etc). Is there much of a benefit to a similar lacquer vs polyurethane varnish? Either fine?

I guess some might think it a bit crazy to spend anytime on something like this! I stumbled across them locally and got them for next to nothing, they'll simply be our dining chairs, so lots of use.

[ian]

There are *black* lines in places, which I assumed were just old splits that had got filled with gunk, but there are lines in odd places where there is no split as well, so I'm not sure what they are.

the "black" lines could be body oils and gunk.

My parents had a set of arm chairs used when watching the TV, after 30-40 years of use, the chairs had black lines where a person's arm would rest