Hi All

We have some outside cupboards with doors made from cedar. In preparation to re-oiling them my wife found that oxi-bleech (I think that's what it's called) was a good way to clean them and vanish is a good source of it. Anyway she cleaned them with it and they came up pretty well.

Several of the doors have drip marks left which are presumably where the rain has been dropping off the top onto the doors directly. These are dark lines running perpendicular to the grain. After some searching she discovered that it could be that the rainbow bringing the natural resins out of the wood.

Anyone know whether this is indeed the case and what the best way of removing them is. I am loathed to sand them all again unless I have to.

Thanks

On 16/05/2018 07:34, wrote:
Hi All

We have some outside cupboards with doors made from cedar. In
preparation to re-oiling them my wife found that oxi-bleech (I think
that's what it's called) was a good way to clean them and vanish is a
good source of it. Anyway she cleaned them with it and they came up
pretty well.

Several of the doors have drip marks left which are presumably where
the rain has been dropping off the top onto the doors directly. These
are dark lines running perpendicular to the grain. After some
searching she discovered that it could be that the rainbow bringing
the natural resins out of the wood.

One possibility is iron impurities from hinges or metal fixings reacting
with natural tannins in the wood when it got wet for a period of time.

Anyone know whether this is indeed the case and what the best way of
removing them is. I am loathed to sand them all again unless I have
to.

I think a picture is worth a thousand words here. If the lines originate
from mild steel fittings then my money is on iron staining.

--
Regards,
Martin Brown

Will take some photos when I get home. I do have some of that from a few nails I had to pin from the front but the rest I can not think is. In one are the water runs off some stainless steel. Not sure if that would cause it?

On Tue, 15 May 2018 23:34:42 -0700 (PDT), wrote:


Anyone know whether this is indeed the case and what the best way of removing them is. I am loathed to sand them all again unless I have to.

Oxalic Acid (widely available on eBay) is the most effective wood
bleach.

https://www.woodfinishsupply.com/OxalicAcid.html

https://www.youtube.com/watch?v=YTHiqtdZMMI

On 16/05/18 07:34, wrote:
Hi All

We have some outside cupboards with doors made from cedar. In preparation to re-oiling them my wife found that oxi-bleech (I think that's what it's called) was a good way to clean them and vanish is a good source of it. Anyway she cleaned them with it and they came up pretty well.

Several of the doors have drip marks left which are presumably where the rain has been dropping off the top onto the doors directly. These are dark lines running perpendicular to the grain. After some searching she discovered that it could be that the rainbow bringing the natural resins out of the wood.

Anyone know whether this is indeed the case and what the best way of removing them is. I am loathed to sand them all again unless I have to.

Beach or caustb canb work, but test on a small area frst. Different
woods react differently and I have no experience of cedar.

Thanks



--
The New Left are the people they warned you about.