wooding/bleaching mast

[dreyer]

Hi all,

Im planning on starting to re-finish my mast on my rhodes 33. It is about 43 feet and oval in shape. It been left rather derilict and as a result all the varnish has gone and the spruce is badly faded. Obviously i would like to get it back to a varnishable state but I am weary of stripping off too much wood.

I had a little dig with a tungsten scraper but it seemed to be just a little rough for the job scraping such a soft wood tore it rather than cut it.
Next up I used some 80 grit paper for another test spot and it came up alright but there is still some grey in parts of the grain. Is this a candidate for bleaching or am i going about things the wrong way?

After the two tests my current plan of attack is going to be block back with 60 grit then work my way up to 220 and varnish.

I have little experience using bleach other than on teak decking.

Can anyone offer some advice for me?

Thanks,
James

[pcford]

work up to 120. bleach with oxalic acid. sand with 120. use good dust protection!!! not just a gauze mask. 3M rubber mask or similar. sand as high as you wish to go...frankly for spars, I might sand with 180 after the 120 and call it a day.

protect yourself. oxalic acid is bad.

[Dave Thibodeau]

Be very careful using Oxalic acid on soft woods such as your spars, it is easy to eat away the wood and create little grooves

[Bob Cleek]

Yes to both of the above! Oxalic acid is fine, but don't scrub or abrade the wood because it will soften the soft wood between the grain somewhat. Be sure to wash and rinse well. Be sure to wear rubber gloves when using oxalic acid. It isn't particularly corrosive when mixed as directed, but it will get under your fingernails and then, maybe four or five hours later, well... the pain is indescribable and will last for days!

Don't expect bleach to do a whole lot. It will bring up the color a shade or two, but the dark grey weathering will have to be sanded off. If you use a scraper at all, be sure to scrape with the grain, not against it. That is what caused your problems with scraping you describe.

[dreyer]

Excellent advice folks.

I dont have any oxalic acid on hand but i do have a few gallons of a gentle one part teak soap that we use on deck on the yacht i work on. Generally applied with a white scotchbrite pad once every 4 months or so. Would this be worthwhile?
Its really gentle if used across the grain and brings a rich dark colour back to the teak (which is plantation growth/pretty soft) without removing too much pith.

Would this be ok for a softwood after I run over it with 120? I imagine it cant be bad?

[sdowney717]

http://www.cheoylee41.com/Refit1.html

found some pictures of a spruce mast being reworked.
And they painted it with awlgrip

I just recently cleaned up my deck using an electric Karcher pressure washer.

I used the fan spray and it removed every bit of dirt, algae and grey wood plus it did not groove or dig into the wood. This is your standard treated pine deck. And I dont know how soft your wood is in comparison. The wood looks like new.

It was so easy. I bet if you were careful it would clean up the mast well. The electric Karcher are quiet and not as powerful as the gas driven pressure washers.

[David Conard]

I did a similar project a few years ago, but on two much smaller masts (18 and 25 feet). Because the spruce is so soft I didn't use anything coarser than 100. I did a light bleaching and then used a light stain to blend so the new whiter spruce would not have such contrast with the areas that still had some grey stain. Most importantly I followed Margo's advice to mark a spot 10' above the deck and to be less compulsive with the areas above that. It's not a new mast, and it will have some "patina."

[dreyer]

it will get under your fingernails and then, maybe four or five hours later, well... the pain is indescribable and will last for days!



Haha. I remember using a 2 step teak treatment on a large yachts decks while wearing only boat shoes. 1st soap & scotchbrite then an acid wash to brighten. About 2 weeks later the soles of my feet peeled off!!! Not good. :) We use some wonderfully harmful products on boats dont we..

[Wild Wassa]

Using a tungsten carbide scraper is a balance between a light touch and fast speed. The blade needs to be kept clean and undamaged, remain as sharp as, turned over or replaced often and kept away from fasteners and all hardware ... super light and super fast, that is how I find that the tool works best. The more shavings produced the better the blade has worked and the tool correctly handled.

When I am scraping, I turn the blade slightly at an angle to the direction of the pull. This reduces a tendancy for the blade to stutter. The scraper shaves the paint off, it does not drag or bludgeon the paint off.

Good blade work using a tungsten carbide blade should do two jobs at the same time ... it removes the majority of the paint and slightly dresses the timber, reducing much of the need to sand.

Warren.

[dreyer]

Hi all here is a mast update.

I gave up on the scraper as it was just doing too much damage to the wood. Sweat and some good 3m P80 grit has sufficed so far.
Im about 60% done on the heavy sanding. Margo's advice about not being so picky above the first spreaders is a good one. Its looking good with only a few dark stains here and there which i can live with and the patina shows that she has lived a hard life.

Above the jumper spreaders (in bottom pic) is fairly thin and I am getting swung by the idea of painting the top 5 feet or so white. It will mean less maintenance aloft in the future and i will not have to sand back an already pencil like section of mast. What are peoples thoughts on this (functional, personal, aesthetic)?

Also mentioned below is the luff channel. How would you attack this? Open to all suggestions of course.

http://img528.imageshack.us/img528/207/img2404oi9.jpg (http://imageshack.us)
First area I attacked. There is goodness beneath!

http://img529.imageshack.us/img529/5816/img2398pn0.jpg (http://imageshack.us)
Im a bit weary of my luff channel. Minimal sanding in this area and live with the fact it will be grey methinks. Expensive option would be to cut this back and glue in a new channel section of spruce. Would mean i can be confident of its strength as i dont really want to have to pull the mast again in a hurry. Do it once do it right sort of thing.

http://img516.imageshack.us/img516/492/imgp3177xd8.jpg (http://imageshack.us)
The full rig (just after i bought her) Fairly large stick for a 34' boat!

[sdowney717]

high pressure washing again mentioned, But i think you should work harder doing this by hand stripping and sanding.
If you want the groove easily cleaned out a Karcher water pressure machine would work extremely easily and fast.

http://www.peerlesspowerwashing.com/information.html



Organic Growth Removal and High Pressure Water Washing

Mold and mildew are the dark gray or black growth we see on wood. All organic growth must be completely removed through surface stripping, high pressure water washing or a combination of the two. The restoration professionals generally uses a combination of the two to more efficiently remove the top layer of weathered wood (gray wood) and organic growth at the same time. The process involves application of a diluted stripper (best) or special wood bleach) followed by high pressure water washing.

[Dave Johnson]

I refinished several masts by belt sanding away all the old finish and then I used regular two part wood bleach [hydrogen peroxide and sodium hydroxide]. Let the hydrogen peroxide dry to a white color and then apply the sodium hydroxide. This needs to be neturialized with "TSP" trisodium phosphiate and water. This process takes most of the black spots out of the sitka and of course it raises the grain which helps when you sand the wood to get it ready for varnish.

Any paint store carries these products.

[dreyer]

alrighty...

bleached, blocked with 150 & hung up ready for CPES.

I imagine that with two coats of cpes over a 12 hour period that i would not have to thin my coats of epifanes at all as it wont do any penetrating??

Tomorrow i bolt in the last 4 floors, get some coats on the mast, finish welding up my cradle and she is ready to heat to Doug jones at traditional boat works san diego.

Man i feel a sense of achievement rushing towards me.

:)

[David G]

Hi all here is a mast update.


Above the jumper spreaders (in bottom pic) is fairly thin and I am getting swung by the idea of painting the top 5 feet or so white. It will mean less maintenance aloft in the future and i will not have to sand back an already pencil like section of mast. What are peoples thoughts on this (functional, personal, aesthetic)?



In my short boatbuilding career, I've only done 4 spars. All varnished. However, in my decades as an architectural millworker, I've done maybe a dozen flagpoles. One point I've always mentioned to property owners is that it's much easier to keep track of what's going on with the wood under a clear finish than under an opaque finish.

The paint, however, is a bit more inherently durable, and also better protects the underlying wood from UV degradation. It seems like it's not uncommon to see spar tips painted white. Still - I'd only be inclined to do so if my spar was easily accessible - so I could keep an eye on it, and touch up as necessary. Maybe I'm a Nervous Nellie, but I've rebuilt several painted flagpoles. One had snapped off in a blow without looking all that bad beforehand. Several showed only the slighted evidence of finish failure, yet the stick itself was very punky under the paint.

"It is the dull man who is always sure, and the sure man that is always dull" -- H.L. Mencken

[Jay Greer]

Having stripped four large masts this year, including one for a Rhodes 33, I found that only one thing differs from the way I did it in the past.
We are now using an aircraft known as Star 10. This material does not attack the skin in the manner that other removers do. Additionally, the fumes are kinder to the nose! But this stuff does work better than other materials do. The trick is to lay on a thick coat, without re-brushing, and then go have a cup of coffee or a beer. Next lay on another coat over the finish that is starting to bubble. Have another beer. Repeat the process two more times. If you are still standing, the finish should now be turned to jello and showing some actual bare spots. Wearing gloves, scrub down the mast with a medium 3M pad (Green), in combination with a high pressure hose. If any areas are still not clean, follow up using the part B Star 10 Stripper and medium bronze wool. Some areas may need the light touch of a scraper. But normally this is not needed. Stripping a
spar the size of a Rhodes stick takes me about an hour and a half. Once dry, the spar can be sanded with a long board or air file using 100 grit paper. Once the first sanding is done, super saturated hot oxolic acid can be painted on. Bleaching normally takes more time than stripping. Always apply the solution hot using a glass container and throw away brush. If stains persist, the wet spar can be wrapped in visquine and allowed to cook over night. Next day, using a fine 3M pad, the acid should be thoroughly rinsed off. After the mast is dry it can then be sanded with 120 followed by 180 grit paper prior to varnishing.
Jay