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JimD
06-15-2014, 11:11 AM
This teak is off my friend's boat. I said I'd see what i could do to to bring it back to its former glory. There are two of these rails. They are about 10 feet long. Only the end four feet that is constantly exposed to weather are this bad. Suggestions on removing the old varnish and sanding/treating the the weathered exposed sections welcomed.

http://im1.shutterfly.com/media/47a4d834b3127ccef60a2b486c1c00000030O00CbOGrVu4cMQ e3nw8/cC/f%3D0/ls%3D00108875580620140615155031649.JPG/ps%3D50/r%3D0/rx%3D550/ry%3D400/http://im1.shutterfly.com/media/47a4d834b3127ccef60a990ced3100000030O00CbOGrVu4cMQ e3nw8/cC/f%3D0/ls%3D00108875580620140615155552650.JPG/ps%3D50/r%3D0/rx%3D550/ry%3D400/

David G
06-15-2014, 12:28 PM
You could use stripper. But at that state of decrepitude... I'd make my first efforts with a heat gun and scraper. Then sand. If there's too much discolaration left after a reasonable amount of sanding... or too much variation between weathered areas and not... then I'd consider a stain before varnishing (fotos are always limited - but it looks like it may have been stained at one point). I like the Pettit line of stains... but there are several contenders.

JimD
06-15-2014, 12:32 PM
You could use stripper. But at that state of decrepitude... I'd make my first efforts with a heat gun and scraper. Then sand. If there's too much discolaration left after a reasonable amount of sanding... or too much variation between weathered areas and not... then I'd consider a stain before varnishing (fotos are always limited - but it looks like it may have been stained at one point). I like the Pettit line of stains... but there are several contenders.

I was thinking stripper, too. The varnish that's on is several layers, as it should be. On these bad ends it sort of chips off like tree bark but at the good ends (not shown) its held up rather well and I'm wondering if its necessary to strip the entire length. I suspect it is. I'll probably pick up some stripper and take the whole thing down to bare wood. I haven't tried sanding those bad ends yet.

slug
06-15-2014, 12:47 PM
Varnish Looks pretty bad. Perhaps give that stick of wood to a dog and let him chew it off.

If youre not in a rush you could just leave the wood outside and let the remaining varnish fall off.

JimD
06-15-2014, 12:51 PM
Varnish Looks pretty bad. Perhaps give that stick of wood to a dog and let him chew it off.

If youre not in a rush you could just leave the wood outside and let the remaining varnish fall off.

The neighbours have a pitbull. I could accidentally toss them over the fence ;)

Bob Cleek
06-15-2014, 01:36 PM
Wrong. Teak is never stained.

JimD
06-15-2014, 01:39 PM
Wrong. Teak is never stained.So Bob, if I sand enough of the surface away will it stop looking like driftwood? And if so, how much will I have to sand?

Bob Cleek
06-15-2014, 01:46 PM
I was thinking stripper, too. The varnish that's on is several layers, as it should be. On these bad ends it sort of chips off like tree bark but at the good ends (not shown) its held up rather well and I'm wondering if its necessary to strip the entire length. I suspect it is. I'll probably pick up some stripper and take the whole thing down to bare wood. I haven't tried sanding those bad ends yet.

A heat gun and a good scraper are the proper tools to remove the varnish. It must all be removed. You will never match the old and the new.

Step 1. : Heat gun and scraper to remove varnish (or as Slug suggests, let the sun strip it!)

Step 2 : Bleach with oxalic acid solution in water. (Buy oxalic acid crystals as "wood bleach" in any paint store. DO NOT use "tek-a, teak brite" or any such bottled formulations, which are way too strong and will eat the softwood between the grain.) Apply mild acid solution as per instructions on container, repeatedly, until teak is uniformly honey colored. (It will be darker, like when varnished, when it is wet and very light tan when dry.)

Step 3 : Rinse well with soapy water to neutralize the residual acid crystals. Let dry.

Step 4 : Sand raw wood smooth. (There is no point in sanding varnish off of wood unless you are interested in spending a lot of money on sandpaper and certainly no point in sanding it to raw wood rather than bleaching... unless you just want to make a lot of expensive teak sanding dust.)

Step 5 : Seal well with CPES (or thinned varnish, if you are a purist... pick your poison.)

Step 6 : Apply varnish.

Perhaps the most amazing property of teak is its ability to be bleached to "as new" condition. It doesn't ever need to be stained for any reason whatsoever.

Bob Cleek
06-15-2014, 01:48 PM
So Bob, if I sand enough of the surface away will it stop looking like driftwood? And if so, how much will I have to sand?

I guess our posts crossed in the mail.

Oxalic acid wood bleach will remove the "driftwood look" used as per the directions without any sanding at all. There is no point in trying to sand off the "driftwood" look because you are just wasting sandpaper removing wood that doesn't need to be removed. (Just sand right before you begin to apply finish coatings so the surface is fair.)

Wear gloves with the bleach because it will otherwise get under your fingernails and, hours later, hurt like a mother...

You should be able to see the bleaching action immediately, sort of like developing a black and white photo in a darkroom. The more you sponge on, the lighter the teak gets until it won't get any lighter. Then you know you are there. Don't go crazy scrubbing the wood with Scotchbrite pads and NEVER use steel wool anywhere near a boat. (Can you say "little tiny rust spots everywhere...") If you scrub too hard, you'll remove the soft wood between the grain and the surface of your piece will look like a pair or corduroy pants.

Not to hurt anybody's feelings here, but there were some flat out wrong answers given. Refinishing teak correctly is not rocket science and it sure isn't a subject of debate.

slug
06-15-2014, 01:49 PM
Teak bounces back to life once you sand off the grey , oxidized surface layer.

A sharp wood scraper and heat or chemical paint remover, followed by sandpaper would be the way trim is brought back.

JimD
06-15-2014, 01:56 PM
A heat gun and a good scraper are the proper tools to remove the varnish. It must all be removed. You will never match the old and the new.

Step 1. : Heat gun and scraper to remove varnish (or as Slug suggests, let the sun strip it!)

Step 2 : Bleach with oxalic acid solution in water. (Buy oxalic acid crystals as "wood bleach" in any paint store. DO NOT use "tek-a, teak brite" or any such bottled formulations, which are way too strong and will eat the softwood between the grain.) Apply mild acid solution as per instructions on container, repeatedly, until teak is uniformly honey colored. (It will be darker, like when varnished, when it is wet and very light tan when dry.)

Step 3 : Rinse well with soapy water to neutralize the residual acid crystals. Let dry.

Step 4 : Sand raw wood smooth. (There is no point in sanding varnish off of wood unless you are interested in spending a lot of money on sandpaper and certainly no point in sanding it to raw wood rather than bleaching... unless you just want to make a lot of expensive teak sanding dust.)

Step 5 : Seal well with CPES (or thinned varnish, if you are a purist... pick your poison.)

Step 6 : Apply varnish.

Perhaps the most amazing property of teak is its ability to be bleached to "as new" condition. It doesn't ever need to be stained for any reason whatsoever.

Mucho obliged, Bob. Will pick up the oxalic acid today.

Bob Cleek
06-15-2014, 02:00 PM
Teak bounces back to life once you sand off the grey , oxidized surface layer.

A sharp wood scraper and heat or chemical paint remover, followed by sandpaper would be the way trim is brought back.

And also when it is properly bleached. The problem with sanding oxidized (weathered) teak is that you may have to sand a whole lot more than you thought to get deep enough to sand out a gouge or divot or whatever and the whole shape of your piece changed. There are tens of thousands of beautiful traditionally built teak decks that have had to be replaced because they were spitting their plugs and that because some horse's ass decided to "get rid of the driftwood look" with a belt sander.

David G
06-15-2014, 02:14 PM
I guess our posts crossed in the mail.

Oxalic acid wood bleach will remove the "driftwood look" used as per the directions without any sanding at all. There is no point in trying to sand off the "driftwood" look because you are just wasting sandpaper removing wood that doesn't need to be removed. (Just sand right before you begin to apply finish coatings so the surface is fair.)

Wear gloves with the bleach because it will otherwise get under your fingernails and, hours later, hurt like a mother...

You should be able to see the bleaching action immediately, sort of like developing a black and white photo in a darkroom. The more you sponge on, the lighter the teak gets until it won't get any lighter. Then you know you are there. Don't go crazy scrubbing the wood with Scotchbrite pads and NEVER use steel wool anywhere near a boat. (Can you say "little tiny rust spots everywhere...") If you scrub too hard, you'll remove the soft wood between the grain and the surface of your piece will look like a pair or corduroy pants.

Not to hurt anybody's feelings here, but there were some flat out wrong answers given. Refinishing teak correctly is not rocket science and it sure isn't a subject of debate.

I have no problem with most of your approach. I disagree strongly, though, with the bleach only - no sanding - comment. I think from the rest of what you said, you may be confusing how to treat a teak surface that needs no, and received no, finish... with the brightwork bits. I'd agree with you if you were talking about a deck, or some other component that the owner wanted to have 'that' look. But the part in question is varnished. And when a bit of teak has been left to weather for as long as that one has... the wood itself degrades. The outer surface has lost its oils, and the lignin has broken down. Without any sanding, the varnish job will only be as strong as the bond between that loose surface layer of wood and the underlying 'good' wood.

And... doesn't it appear to you that these teak components WERE stained under the prior varnish job? It looks like it to me.

JimD
06-15-2014, 02:40 PM
Here's what a very quick light sand with the ROS did. Some colour coming up but still quite grey. Not sure how much more wood I want to sand off. Also I've emailed the owner to see if he wants to do next.

http://im1.shutterfly.com/media/47a4d834b3127ccef60ba349cd2500000030O00CbOGrVu4cMQ e3nw8/cC/f%3D0/ls%3D00108875580620140615193647934.JPG/ps%3D50/r%3D0/rx%3D550/ry%3D400/

Compare to before pic:

http://im1.shutterfly.com/media/47a4d834b3127ccef60a2b486c1c00000030O00CbOGrVu4cMQ e3nw8/cC/f%3D0/ls%3D00108875580620140615155031649.JPG/ps%3D50/r%3D0/rx%3D550/ry%3D400/

JimD
06-15-2014, 02:42 PM
And... doesn't it appear to you that these teak components WERE stained under the prior varnish job? It looks like it to me.

Could that be just a thinned first coat of varnish? I have no idea. Just asking.

David G
06-15-2014, 03:12 PM
Could that be just a thinned first coat of varnish? I have no idea. Just asking.

It's just that I've never seen that shade of red/brown on natural teak. But... as I said... fotos can be misleading. What's the rest of the brightwork look like? Any clues there?

JimD
06-15-2014, 03:18 PM
It's just that I've never seen that shade of red/brown on natural teak. But... as I said... fotos can be misleading. What's the rest of the brightwork look like? Any clues there?

The photos are quite accurate so that's what the wood looks like. Not a lot of clues from the rest as there isn't much on the boat.

JimD
06-15-2014, 06:34 PM
We've decided not to bleach. I'll post pics after I get half a dozen coats of Epiphanes on them.

David G
06-15-2014, 06:37 PM
I'd suggest you prep and varnish the backside as well. Once the backside is prepped, put a sample coat on it - and see if it's the color you want? I'm still thinking that the original was stained. Not that your pieces HAVE to match the original... it's an aesthetic decision for the owner.

JimD
06-15-2014, 06:46 PM
I'd suggest you prep and varnish the backside as well. Once the backside is prepped, put a sample coat on it - and see if it's the color you want? I'm still thinking that the original was stained. Not that your pieces HAVE to match the original... it's an aesthetic decision for the owner.

The owner's not concerned about it. We talked it over and he said just remove the old, brush on the new, and it will be what it will be. Below in the cabin its almost all brightwork but on deck where these rails go there's almost none so it won't look out out of place. It might not look that good, either. But its a Jeanneau in FG and few will even notice it has any brightwork.

David G
06-15-2014, 06:51 PM
Voila' and Shazzam! You're good to go!!