Interior varnishing

[GWB]

Hi all -

I'm about to start this project. My boat was built 35 years ago in Tucson Az. The interior is teak, mahogany and some ash..... the bulkheads are mahogany veneered plywood.
The builder oiled the wood years ago and nothing since. He was a smoker and so the dust in Tucson and smoke etc have made the wood dirty.

1) I'm unsure about how to clean the wood. Some have told me to use a product like Te-Ka to wipe it down....others have said Murpheys oil soap. Perhaps I should just sand it?
Part of what I'm trying to achieve is to lighten the wood to its original color as the oil has darkened it.

2)The second part of my question is which varnish should I use to keep the wood "lighter" looking. I have used Interlux schooner but it has a slight yellow effect......and how many coats.

I would greatly appreciate some help with this...I don't want to get it wrong.

Our blog is here: http://westsail32.blogspot.com/
If you go to the first few entries there are some pictures of the interior.

Thank you in advance for help with this
Gary

[kc8pql]

Part of what I'm trying to achieve is to lighten the wood to its original color as the oil has darkened it.
Can't be done without sanding down to bare wood, a very risky if not imposable thing to do with plywood.

[GWB]

So you think that the oil could have penetrated the surface veneer all the way to the glue line?
Thanks for the response


Can't be done without sanding down to bare wood, a very risky if not imposable thing to do with plywood.

[Lew Barrett]

You can try using a chemical stripper. Pick a small unobtrusive spot to start.

Be careful and make sure your scraper is sharp. I use exterior varnish on the interior. Detco's Crystal is colorless, although it's not a product I have much experience with.

[David G]

Can't be done without sanding down to bare wood, a very risky if not imposable thing to do with plywood.

Sorry, I have to disagree. It's true, only a very experienced hand has any chance of sanding this sort of project without burning thru the veneers. But that's OK, cause you aren't likely to get where you're going by sanding anyway.

It's hard to diagnose from a distance, but I suspect you could accomplish something useful with stripper or a solvent wash, or a cleaning product. I have less experience with the latter, though I have heard of Te-Ka. That route would be my first attempt (because it is the mildest, least messy/toxic). Follow the instructions... and as always, try it out first in an innocuous location.

If the cleaning isn't sufficient, you might follow it with a solvent wash. Bucket of solvent, damp (not sloppy) rag, rinse often and change your solvent often. Lots of fans running. LOTS! And don't even try so much as a corner without your respirator on.

Another thought - instead of a rag, you could add a slight bit of scrubbing action by using the finest Scotchbrite pad (is it maroon?... I forget).

The biggest hassle - and the surest of success - is to use a stripper. Given that you're cleaning up an oil finish, it wouldn't take a lot, but it's sloppy, messy, stinky work. Again, heavy on the ventilation and respirator.

And - when it comes time to put the new finish on - you might start your finish schedule with a coat or two of shellac, or Zinnser Seal Coat (a light cut of shellac, with some additives to make it sand easier). The shellac will help seal in any contaminants which might cause compatibility problems with your varnish. It also adds color and depth to a clear finish. Additionally - it sands to a Very Smooth surface - which gives your varnish a very nice base.

G'luck


"I'm tired of all this nonsense about beauty being only skin deep. That's deep enough. What do you want, an adorable pancreas?" -- Jean Kerr

[kc8pql]

So you think that the oil could have penetrated the surface veneer all the way to the glue line?
Thanks for the response
Yes. The veneer is only 1/28" thick at best, more likely it's 1/40".
Stripping and bleaching may lighten things somewhat, but it's very unlikely to bring it back to it's original color. It's more likely you'll end up with light and dark splotches.

[GWB]

Lew - what do you use on the interior?


You can try using a chemical stripper. Pick a small unobtrusive spot to start.

Be careful and make sure your scraper is sharp. I use exterior varnish on the interior. Detco's Crystal is colorless, although it's not a product I have much experience with.

[Peter Malcolm Jardine]

I sometimes use a mild solution of TSP and water, which removes grease and dirt. I often use a tinted varnish, using artists umber for mahogany color. It's a cheat, but it doesn't cloud the varnish much if used in small quantities, and it evens out color when either UV or age has attacked color. I always use a satin finish varnish, in this case Epifanes matte finish. It is more forgiving of color differences and defects as well.

[GWB]

I measured a piece - it is .038" :eek:

Do you think just cleaning it will have to do?.......and with what :confused:


Yes. The veneer is only 1/28" thick at best, more likely it's 1/40".
Stripping and bleaching may lighten things somewhat, but it's very unlikely to bring it back to it's original color. It's more likely you'll end up with light and dark splotches.

[GWB]

Yes - I have heard of using TSP. What is the dilution ratio that you use?
I thought maybe satin for the large flat areas and gloss for the trim pieces - did you say you would use Epifanes matte if you were doing my boat Peter?
Thanks for the response


I sometimes use a mild solution of TSP and water, which removes grease and dirt. I often use a tinted varnish, using artists umber for mahogany color. It's a cheat, but it doesn't cloud the varnish much if used in small quantities, and it evens out color when either UV or age has attacked color. I always use a satin finish varnish, in this case Epifanes matte finish. It is more forgiving of color differences and defects as well.

[Jay Greer]

Better than TSP is a solution used for removing pitch and gum from saw blades called CMT Pitch & Gum Remover.
http://www.highlandwoodworking.com/index.asp?PageAction=VIEWPROD&ProdID=1288
This non caustic solvent can be spayed on most any dirty surface and wiped off with a fine Scotch Bright Pad. It will remove gummy oil and dirt as if by magic.
If a dark rich finish for interior teak trim is desired, it can be sealed with orange shellac prior to the application of the varnish. Shellac is most, effectivaly, applied with a pad that is not super saturated with the material. This will obviate lap marks. The surface can then be sanded with 220 grit paper and finished with varnish. Either rubbed effect varnish or gloss can be used. Gloss varnish can be rubbed out with a mixture of mineral oil, naptha and pumice using fine bronze wool or a fine 3M pad in order to remove the reflective gloss. This can be followed by the application of paste wax if a soft shine is desired.
Jay

[GWB]

Jay - this product looks very interesting. Will it bleach the wood?


Better than TSP is a solution used for removing pitch and gum from saw blades called CMT Pitch & Gum Remover.
http://www.highlandwoodworking.com/index.asp?PageAction=VIEWPROD&ProdID=1288
This non caustic solvent can be spayed on most any dirty surface and wiped off with a fine Scotch Bright Pad. It will remove gummy oil and dirt as if by magic.
If a dark rich finish for interior teak trim is desired, it can be sealed with orange shellac prior to the application of the varnish. Shellac is most, effectivaly, applied with a pad that is not super saturated with the material. This will obviate lap marks. The surface can then be sanded with 220 grit paper and finished with varnish. Either rubbed effect varnish or gloss can be used. Gloss varnish can be rubbed out with a mixture of mineral oil, naptha and pumice using fine bronze wool or a fine 3M pad in order to remove the reflective gloss. This can be followed by the application of paste wax if a soft shine is desired.
Jay

[GWB]

Thank you very much for all the responses.
Will TSP in a mild soultion have to be removed from the wood after cleaning? In other words, will I have to use just clean water to rinse after I use the TSP?

[kc8pql]

Will TSP in a mild soultion have to be removed from the wood after cleaning? In other words, will I have to use just clean water to rinse after I use the TSP?
Yes, just a lite rinse. TSP is the same thing your mother/grandmother used to wash the kitchen linoleum, Spic and Span.

[Jay Greer]

Jay - this product looks very interesting. Will it bleach the wood?
It may remove oil based stains. Other wise, hot oxolic acid and a sun lamp is the last resort. Although there are other bleaches available such as chlorine and two part peroxide bleach, they are too powerful and will remove all color from the wood and deaden the grain pattern. They are not applicable for the purpose you need. TSP will have to be rinsed with fresh water after application as it may leave white film of dust on the surface after drying. Pitch and gum remover will not.
Jay

[Lew Barrett]

Lew - what do you use on the interior?

Epifanes. That work is all old now, but there you go. I am using Flagship these days as well. I am perfectly happy to use an exterior spar varnish inside.

[pcford]

A point that should be made about interior varnish is that if one wants to do a satin finish via satin finish varnish, the satin varnish should be used for the last couple coats only. If satin is used though the build, the varnish will not be as clear as it should be. The same properties that create the satin finish also make the varnish less clear.

I recall seeing a Hans Christian which had satin varnish used through the varnish build...looked bad ...obscured the grain.

[GWB]

Good tip - thank you


A point that should be made about interior varnish is that if one wants to do a satin finish via satin finish varnish, the satin varnish should be used for the last couple coats. If satin is used though the build, the varnish will not be as clear as it should be. The same properties that create the satin finish also make the varnish less clear.

I recall seeing a Hans Christian which had satin varnish used through the varnish build...looked bad ...obscured the grain.

[C. Ross]

If Jay says something is good I would try it - I've never used that product but IMO his advice is always sound.

But another vote for TSP for removing oil from teak -- I had great success restoring a badly oiled /darkened teak deck. But I have found that TSP will seriously degrade varnish and will take color out of fabric. So if you are going to TSP your interior be very careful to use plastic dropcloth and solvent-resistent masking tape on anything you don't want to TSP.

[GWB]

I'm going to start with TSP and hopefully that will be enough to get it clean. After that varnish with Epifanes gloss finish

Thanks for all the help I'll post pictures when I have something to show

[Scott Rosen]

Detco's Crystal is colorless, although it's not a product I have much experience with.

It's my varnish of choice for everything but cabin soles (too soft). It's definitely not colorless. It as as amber as the most traditional varnishes. It will noticiably darken tropical woods like teak. On my spruce oars and cedar dinghy thwarts, it imparts a gentle amber color, but is still pretty light.

The clearest, most colorless finishes in my experience are the varnishes made from 100% polyurethane resins.

[Roger Cumming]

I would definitely not use a glossy exterior varnish in the interior of a boat. I have used Interlux rubbed effect varnish in the interior, including the cabin sole, with very good results. It protects the wood and doesn't look like varnish. I think Jay's advice on surface preparation are worth trying.

[pcford]

I would definitely not use a glossy exterior varnish in the interior of a boat. I have used Interlux rubbed effect varnish in the interior, including the cabin sole, with very good results. It protects the wood and doesn't look like varnish. I think Jay's advice on surface preparation are worth trying.

Many people do use gloss varnish inside..but in any case, as I said above, gloss should be used for build coats.

[GWB]

Why not Roger?


I would definitely not use a glossy exterior varnish in the interior of a boat. I have used Interlux rubbed effect varnish in the interior, including the cabin sole, with very good results. It protects the wood and doesn't look like varnish. I think Jay's advice on surface preparation are worth trying.

[Lew Barrett]

It's definitely not colorless. It as as amber as the most traditional varnishes. It will noticiably darken tropical woods like teak. On my spruce oars and cedar dinghy thwarts, it imparts a gentle amber color, but is still pretty light.


My bad.

[kayakn]

if you decide not to strip,sand,varnish, then you can use lemon oil on it and it will look like almost new depending on how bad the wood it.

[sdowney717]

citri-strip, the orange stripper. It has worked well for me.
I strip, scrape, then I use oxalic acid to brighten the wood.

I also use a safety razor to scrape the mess off
you can avoid most sanding this way.

[Roger Cumming]

GWB, my preference for the rubbed effect varnish in lieu of the glossy exterior varnish in the boat's interior is purely visual. Like a room in your house painted in a glossy paint, every imperfection will be highlighted. The gloss in varnish helps to protect against the effects of sunlight - unnecessary in the interior of a boat. Interior varnished surfaces get very little wear, nothing like the exterior. Occasional touch-up here and there is all that is necessary. The rubbed effect varnish is easier to apply than glossy varnish or paint and in my experience lasts longer.

[Jay Greer]

Here are a few notes on rubbed effect varnish. Bear in mind that the finish is softer than gloss varnish due to the silica additive to produce a flat finish. It must be well stirred and is only intended for two or more finish coats in order to allow full coverage of the matt finish. If indeed one desires a traditional flat finish that is also enhanced by paste wax, the proceedure is to rub the varnish with a mixture of oil pumice and naptha or white gas using either a bronze wool pad, terry cloth rag or a felt block, for panel work. Rubbing out gloss varnish can be a better way to go as, "rubbed effect" varnish is softer than gloss varnish and is more prone to damage by scuff or impact.
Jay

[pcford]

Rubbing out gloss varnish can be a better way to go as, "rubbed effect" varnish is softer than gloss varnish and is more prone to damage by scuff or impact.
Jay

I have no way of knowing if satin (rubbed effect) varnish is in fact softer than gloss. But I can highly recommend it for its beauty. The labor involved is not excessive; the cost is modest. It produces a finish which is silky smooth and has a warm glow. Very sexy.

I've used pumice followed by rottenstone. As a lube I've used water and rubbing oil. I don't like the idea of using naptha or white gas. Naptha is a carcinogen and white gas...well...it just does seem a good idea to have gasoline loose inside a boat.

Wonderful look though. Try it!

[Jay Greer]

I have no way of knowing if satin (rubbed effect) varnish is in fact softer than gloss. But I can highly recommend it for its beauty. The labor involved is not excessive; the cost is modest. It produces a finish which is silky smooth and has a warm glow. Very sexy.

I've used pumice followed by rottenstone. As a lube I've used water and rubbing oil. I don't like the idea of using naptha or white gas. Naptha is a carcinogen and white gas...well...it just does seem a good idea to have gasoline loose inside a boat.

Wonderful look though. Try it!
I might add, that using naptha or white gas allows one to almost instantly know how the work is progressing, as it drys fast. This is the traditional method used in restoration of wooden art objects, which is one of my side lines. Certainly I am not foolish enough to work with out adequite ventalation and spark supression. I do appolgise for not mentioning that I also wear protective gloves plus a toxic chemical filtration mask when working with carconogenic materials.
I would not consider doing otherwise.
Jay

[meuritt]

I can vouch for TSP and elbow grease. We did the lower parts of the boat last fall, this weekend I started on the pilothouse. I used about half cup of tsp to less than a gallon of hot water, and even with that it took four washes, each with fresh solution, to get to tea colored water. Sometimes I rinsed between washes and sometimes not, but always when I was done with that section for the day. Went back over everything again after it had dried over night and was amazed at how much grime was still coming off, I would imagine most coming from between the T&G, since the plywood didn't do this.

I have some varnish to deal with inside the PH, but most was left exposed, it had originally been oiled, we plan to use oil, as we did below decks. The TSP has knocked some of the varnish off, I am sure the prep work was not thorough, but i will be taking the heat gun and scraper to it when the washing is all done.

Only planning to re-varnish the nav station table.

Mike
San Rafael, CA