silky oak - caustic dip???

[kathyh]

Hi Folks,
My first time posting - please have patience with me! I have recently purchased some silky oak doors that have been dipped in caustic to strip them. I think it was some time ago and the surface of the wood is a little furry looking. I am hoping to sand and do up for use, however I have been told that the caustic will continue to 'seep' from the timber and will always cause problems. I live in a humid climate that apparently will make this worse.
Any ideas? Should I oil, varnish (oil or water-based) or give up before I start this big job! Thanks in advance - any suggestions appreciated!
Kathyh

[journeyman Mick]

aaaargh! thats probably the worst thing to do to beautiful timber joinery. It tends to strip the colour out (your oak is probably looking whitish grey rather than a rich pinkish red). I haven't heard about the caustic staying active, the chemical reaction would have a finite time depending on the strength of the solution and time immersed/absorbed. Eventually the solution will neutralise itself by reacting with the timber. One way to tell might be by soaking a small area with water and seeing if it becomes slippery, as this would mean that there is still caustic material present in the timber. (Any chemists reading please feel free to correct me here!) If this is the case you could neutralise it by soaking it in vinegar. (I used to do this when I was screenprinting and we reclaimed screens by soaking them in a caustic bath). The other problem is that the caustic attacks the glue in the joints as well as the timber that makes up the joints themselves. This means that after someone goes to all the trouble to strip and refinish their doors or windows they tend to fall apart, or at least sag badly once they are rehung. You need to get the joints in your doors reinforced to stop your door coming apart. I've done this to countless doors & windows on old queenslanders in Cairns. You need to make sure your doors are square, cramp all the joints tight and fix them. Fixing options are:
1) inject joints with epoxy glue - messy but effective.
2)drill a round hole through each joint and drive a tapered square pin through it (a trenail). This is fairly neat and a bit traditional, not as messy as 1 and nicer than 3 & 4.
3) drive a screw through each joint - visible, but fast, effective and secure.
4) drive nails through each joint - fast & cheap but not as secure as 3
If you are in Cairns and you don't feel up to all this, or haven't lined up a carpenter to hang your doors please e.mail me.

Good luck, have fun,

Mick

[Shane Watson]

Depending on how long ago the door was 'dipped' depends on what actions should be taken now. If its recent that it was done then probably a good wipe down with vinigar or oxilic acid wouldn't be out of the question. But if it was done properly to start with, this would have been done at the time of 'dipping'.

The biggest problem with 'dipping' is the length of time the timber is submerged in the solution, the solution being mostly water. So the timber needs to 'season' again or dry out. So if the process was done a good time ago the moisture content should be back to a stable level.

The furry stuff will just sand off easily and depending on how strong and how long the door was submerged will dictate how much sanding is required to get back to the timbers natural colour.

Re-finishing is your choice. Unfortunatly I would suggest to expect problems in the long term, but at the same time I ain't suggesting you will have any problems. Choice of finish is again your choice.

Frankly when it comes to this situation I just re-paint or if I want that timber look, I build replica's - usually less work in the end & you can use the timber from the existing piece, but thats a whole other story.


Cheers, oh and welcome to the board, have fun, ask questions, give anwers, hassle stoppers, whatever takes your fancy but enjoy!

Shane.

PS, all the work I was involved in that relates to Caustic soda was also in NQ..

[kathyh]

Thanks Shane and Mick.
Mick, you just need to be a little closer ! I am near El Arish so just a bit far afield to hang doors - thats a fair way off happening yet anyway.
I will have a good look at them and work out the best way of fixing the joints. The timber dosen't look too washed out so I am hoping that a good sanding will revive the colour. Thank you for your most welcome advice - I think this site could be a very useful and informative one. Cheers!
Kathy