Captain Crisp
Active member
Evening all.
What are the steps for renovating my badly stained mahogany cockpit surround?
Many thanks,
Crisp
What are the steps for renovating my badly stained mahogany cockpit surround?
Many thanks,
Crisp
How do I remove stains from mahogany cockpit surround?
- Thread starter Captain Crisp
- Start date
PabloPicasso
Well-known member
Strip the varnish and use oxalic acid. Mine came in Powdered form and was disolved in hot water.
Paint on with a brush, leave for 20min and rinse thoroughly.
Repeat as needed untill desired result acheived.
Prepare wood and finosh as desired
Wear rubber gloves and. Goggles. Its powerful stuff!!
Paint on with a brush, leave for 20min and rinse thoroughly.
Repeat as needed untill desired result acheived.
Prepare wood and finosh as desired
Wear rubber gloves and. Goggles. Its powerful stuff!!
Tranona
Well-known member
Strip all the varnish off to get back to bare wood. This will probably remove most of the staining, but you may well have to use a combination of bleach (or oxalid acid if deep in the wood) and scraping followed by sanding to get back to an even colur. Then apply the coating of your choice.
No short cuts. Plenty of elbow grease and patience to get all the old coating out of the grain and the joints. As your photo shows most of the staining starts at a joint where the coating film has broken down allowing water in. The plugs on the right hand side of the photo may need replacing as it looks like the adhesive they are set in has failed. You won't know how much remedial work is needed until you have stripped it. You may have to experiment with stripping depending on the make up of the coating. I find a combination of hot air gun and Bahco scraper works for most varnishes but some respond better to a chemical paint stripper.
Just to give you some encouragement these teak toe rails, cappings, coamings and rubbing strakes were far worse than yours when I started.
No short cuts. Plenty of elbow grease and patience to get all the old coating out of the grain and the joints. As your photo shows most of the staining starts at a joint where the coating film has broken down allowing water in. The plugs on the right hand side of the photo may need replacing as it looks like the adhesive they are set in has failed. You won't know how much remedial work is needed until you have stripped it. You may have to experiment with stripping depending on the make up of the coating. I find a combination of hot air gun and Bahco scraper works for most varnishes but some respond better to a chemical paint stripper.
Just to give you some encouragement these teak toe rails, cappings, coamings and rubbing strakes were far worse than yours when I started.
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BabaYaga
Well-known member
To my eyes the cappings look more like teak than mahogany.
If so, that could be good news, as teak does not absorb water the way mahogany does och the staining under the lifting varnish may be superficial only. Teak is more difficult to varnish, though. If you convince your self that the caulked seams are sound, one option may be to leave the teak bare.
If I were to do work on this, I would in the process definitely drill out the plugs in the corner piece and replace with some of the right size.
If so, that could be good news, as teak does not absorb water the way mahogany does och the staining under the lifting varnish may be superficial only. Teak is more difficult to varnish, though. If you convince your self that the caulked seams are sound, one option may be to leave the teak bare.
If I were to do work on this, I would in the process definitely drill out the plugs in the corner piece and replace with some of the right size.
Refueler
Well-known member
Oxalic Acid ... BUT not just Oxalic in water ... that will run everywhere and not stay where needed.
Mix a strong solution of Oxalic in hot but not boiling water ... let cool till luke warm ... then add wallpaper paste to thicken the mix ...
While the mix is cooling - scrape back the areas to treat and sand smooth ....
Now apply the Oxalic mix liberally ... leave to do its work ...
Before it dries - scrape off and apply again ... repeat as many times as necessary.
Once its reached max effect ... it will be time to wipe away as much as possible - then wash off with liberal amounts of water ... mop and let dry ..
Next you will need to try match wood stain to bring up the colour to match as close as you can ... I doubt you will ever get it perfect ... you may know a friendly furniture restorer who can guide you with the 'crayons' they use ..
Once stained to near match .. it will then be your favourite varnish .... or lacquer - whichever you usually use.
Mix a strong solution of Oxalic in hot but not boiling water ... let cool till luke warm ... then add wallpaper paste to thicken the mix ...
While the mix is cooling - scrape back the areas to treat and sand smooth ....
Now apply the Oxalic mix liberally ... leave to do its work ...
Before it dries - scrape off and apply again ... repeat as many times as necessary.
Once its reached max effect ... it will be time to wipe away as much as possible - then wash off with liberal amounts of water ... mop and let dry ..
Next you will need to try match wood stain to bring up the colour to match as close as you can ... I doubt you will ever get it perfect ... you may know a friendly furniture restorer who can guide you with the 'crayons' they use ..
Once stained to near match .. it will then be your favourite varnish .... or lacquer - whichever you usually use.
Captain Crisp
Active member
Many thanks all!
It's too cold and damp to varnish, but can I get going on the stripping and oxalic-ing now? Or should I leave that till spring too?
Seasons greetings!
Crisp
It's too cold and damp to varnish, but can I get going on the stripping and oxalic-ing now? Or should I leave that till spring too?
Seasons greetings!
Crisp
johnalison
Well-known member
Not really worth it. You will get more work done when it is warmer with more light and longer days. It's not going to get any worse, so long as you shelter it. In the end, it won't look like new unless you take too much wood off, but there's nothing wrong with a slightly mature look.
PabloPicasso
Well-known member
Much better descriptions than mine there 
. Sometimes replacing parts is easier. I've found old doors a good source of free teak/mahogany. Scavanged from various skips over the years. Shocking that people are throwing away such a valuable resource!!
. Sometimes replacing parts is easier. I've found old doors a good source of free teak/mahogany. Scavanged from various skips over the years. Shocking that people are throwing away such a valuable resource!!
Stemar
Well-known member
The pale marks on the coaming are because the varnish has failed and water's got in, lifting more varnish. If you're going to strip the whole lot, I suggest using le Tonkinois, a tung oil based finish that doesn't lift like that. It gives a high gloss finish that won't lift. A ding in a cockpit seat on my boat came home over winter to dry out, got a quick rub down and a couple of new coats to be good as new. If you want a more satin effect, you can get a matting agent to add.
Refueler
Well-known member
Better to leave till later when a bit warmer ....
I have a lot of jobs to do on two of my boats ... I'm inside and not coming out unless really necessary !!
I have a lot of jobs to do on two of my boats ... I'm inside and not coming out unless really necessary !!
