Winter Sealant for Bare Wood Hull?

I am stripping down the painted wood hull of a 1941 cedar gaff rig. My plan is to stain and varnish it for a natural finish next spring.

Q: What is the best type of sealant to apply to protect the wood all winter long after it has been sanded bare but before varnishing next spring?
I don't want the wood to go unprotected but need something to seal it up that won't interfere with my staining and varnishing it later on. The best thing I can think of is an oil based deck sealant?

Please help - I'm so new at this.

The Sound

 

Don't be tempted to use those porch and deck sealants, like Thomson's, most are wax based and will cause you headaches when it's time for a finish.

The problem with raw wood is it needs to be sealed well to survive a prolonged exposure. Try a very liberal coat of half and half varnish and sprits. You would do this anyway as a first coat, when it's time to varnish the wood in the spring and hopefully it will seal her up enough to survive the winter. Use a good cover and keep an eye on her so it doesn't develop leaks.

You could lather her up with some boiled linseed oil and hope it lasts long enough, but you'd not have any UV protection, which the varnish would provide.

If she's going to have direct sun light hit her bare flanks, she will need protection from the sun or she'll weather. Only a coating that can provide some UV protection can do this.

If it was me, I'd hit her with as many coats of varnish as I can now, then a quick coat of cheap acrylic house paint. I'd then strip off the house paint in the spring and have wood looking like it did in the fall, with a start on the build coats for your varnish work.

 

If I end up putting a coat of varnish on the bare wood - won't this interfere with my staining it later on? I do want to stain it to a darker color - just not now.

Assuming that it won't interfere - What type of varnish should I use? Any marine boat varnish?

 

No! you must stain it first.

You didn't say how big this vessel is.

Is the boat small enough to tarp it? If so you might spend about the same for some plastic sheeting and wrap or partially wrap it up tight all winter. In spring you'd need to lightly re-sand but then you could stain the whole thing same time which I'm sure is what you want anyway.

Wrap it tight along the length but leave the ends open for wind and pussycats.

Some stains seal and stain and some recommentd a separate sealer. Read the directions of the stain you will use and see.

 

correct me if im wrong , but to stain ,the conditions dont have to be as such, for varnishis or gelcoats or epoxie.if you do it now ,you can beat the winter.longliner

 

The boat is 27 feet long. Too long and big to put anything on it that i'm going to have to remove next spring. So whatever goes on it now, has to stay on it.... but I'm confused by the last two posts -
I can put a stainer/sealer in one on the boat?
But the last post is saying to do what ?
Please clarify this for me.
Thanks

 

Most all woods need to have the grain sealed (a sanding sealer or home made brew) to insure even stain coverage, between winter and summer growth in the lumber. Some species are much more likely to have a wide range of density between slow and fast growth wood, in a given plank. This difference in density will cause a mottled effect when stain is applied over raw wood (softer areas suck up more color then harder spots), which is why we even out the absorbs rate with a sealer of some sort. With a sealer in place (thinned varnish works for this) the stain is uniform and doesn't get "blotchy" on you. If you are uncertain what color the wood will have when finished clear (cedar will darken considerably from its raw, sanded state, after varnish is applied) you can get a very good idea by liberally smearing a mineral spirits soaked rag over an area. The wet spot from the spirits, will give a good indication of the wood color when clear finished.

You can pretty much stain anytime you want, but epoxy can have difficulties sticking to some stains, particularly oil based. Each epoxy manufacture has a favorite, so use the stuff they recommend. I personally use pigments in the epoxy, rather then stain. Many stains do act as a sealer, which can hinder the mechanical bond with the wood fibers when epoxy is used. Epoxy likes to soak in, literally grabbing the cellular structure of the wood fibers with the first coat or two. This is one of the reasons it's liked so much and has such a good grip on raw wood. Anything between the epoxy and raw wood can interfere with this bond, so I just tint the epoxy with dry pigment and skip the staining process all together.

Though I don't agree with Flumixt's stain first approach, I do agree with him that a tarp (open at the ends, but well covering the boat) is the best way to provide reasonable protection without going through a finishing step. If much sun light bounces off the snow, ground, near by objects, etc. you'll have some UV damage come spring, but it will not be that bad. As heavy a tarp as you can get (14 x 14 weave, with as thick a mil count as possible) will get you wind, snow, rain and UV protection. Build a tent like structure over the boat (open at the ends, like Flumixt suggested). Some folks use PVC pipe for this, others just furring strips or 2x stock, depending on the size of the boat. Dog it down good, because wind can shred a tarp in a month if allowed to flap around much.

Spar varnish is the stuff you want to use. I buy the good stuff, which costs a small fortune (over $600 for a 5 gallon bucket), but you can be guided by the UV inhibitors in the varnish. Compare labels and get the best you can afford, with the highest UV inhibitor percentage.

 

Wow. That was a great response.

So this is what i need to do:?
1. Don't stain the wood.
2. buy Spar Varnish (which is an epoxy?) - does it come pre-tinted or do I have to get the pigments and tint it myself?
3. Put one coat on it for the winter.
4. Seal up the sides of the boat as you all said - can I just shrink wrap it?

 

You'll find cedar (most of them, there are several dozen different types) will darken up a lot with the first few coats of clear finish. Check with mineral spirits first to see if you want to change the color (it may be dark enough with just a clear finish). If you do want more color, then you can stain, use oil or pigments (wet or dry). There are a few options to changing the color of wood, particularly when darkening it.

Spar varnish is an amber colored (the UV inhibitors give it a lot of it's color) oil based clear finish. In the old days (a hundred years ago) varnish was a different animal, but now it's pretty much a clear oil based paint with some UV inhibitors added to keep the wood from weathering. Varnish isn't epoxy. Epoxy is a two part liquid, that when mixed it cures into a plastic. It's used as an adhesive, a wood sealer and as the base for clear finishes. Epoxy alone offers very little but cost and difficulty to any task, but when used with fillers, reinforcement fabrics or to encapsulate wood its value increases a great deal. If your hull hasn't been encapsulated with a penetrating epoxy or you're planning to sheath the hull with a light weight cloth, set in epoxy (which can still have a clear finish applied), then forget about it.

Yes, a single coat could do, but you should put on enough to cover any dry looking spots that will remain after the first coat. You'll probably need at least two coats to get her to shine all over, which is what you want. These two, thinned coats can be sanded off in the spring, very easily or if it survived the winter nicely, can be used as the base for more coats.

Shrink wrap will probably cause ventilation and trapped moisture issues on your boat. A 30' tarp doesn't cost much, though good ones cost more then the cheapies. Look around the yard you have your boat stored, you'll see several ways to use a tarp to cover your boat for the winter. You'll note, the nicer boats have a pretty fancy rig under their tarps. This is because of the amount of work it will save them come spring, by reducing damage, maintenance and repair in time, cost and materials.

You're not sealing up the sides of the boat, but the whole boat. Water and UV damage comes from above. Rain water, pooling on the decks, in nooks, crannies and the bilge is what causes the vast majority of problems on winter storage boats. Just draping a tarp will not do, it must be able to support snow and shed rain water, plus keep UV rays from bleaching out the planks.

 

The Sound: You are obviously confused here from too much info.

I think what Par is recommending is:

1. Don't stain till next summer
2. Get some spar varnish (it's not epoxy, don't add pigment to the varnish)
3. Thin it down -I'd guess 4-5 parts varnish to 1 part solvent (paint thinner). Anybody?
4. Apply that to your unfinished areas.
5. Cover at least those areas you just treated but let em breath.
6. Stain it next summer over the thinned varnish applied this fall.


I think but not totally sure that Par meant that he doesn't use stain plus varnish but uses colored epoxy instead. This evidently gives him a more satisfactory result. The hint here is you might too.




I think you would find it very instructive to mess with several pieces of cedar first to see what happens with the application of the light varnish then the stain vs staining first. Also staining as per whatever procedure the can says for what ever you buy. Label your samples and keep em for reference. Make notes. You'll see how the different sections assume their colors. You will also see how the finish coat affects the final color. Also note and try the stuff mentioned here. Keep a notebook. It will payoff. Ya got all winter.

You should also similarly experiment with epoxy mixed with pigment.

I once finished a board with some exotic process now forgotten and the whole thing but it came out Olive Drab! In a blue boat. Ugh. Didn't try that again. Glad when the sun ruined that job.

 

Flumixt has it down pretty well. 50% mineral spirits, 50% varnish will make a nice sealer coating. Some folks use more solvent, but I don't think it commutes more material into the wood fibers then a 50-50 mix and the build up is faster.

I use sampling as Flumixt recommends all the time. I'll make up several panels to test finish sequences, stains or find the right mixture of a home made brew, for one reason or another. It's the only way to gets the color or results you want without testing it on the actual work. An example would be 1 part light blue, 1 part cadmium yellow, 3 parts medium red provided me a burgundy like color I needed to match a repaired section of rail a month ago. I can mix this batch again, if I have to, with reasonable precision. Try that with a regular stain.

Cedars will clear finish much darker, so test some of your planking stock with spirits first to check the color.

Staining, if necessary can be done several ways. I prefer to use a dry pigment in epoxy, rather then stain bare wood. I find I can control the color easier and build up bulk faster. In ideal conditions, varnish takes a full day to dry, before you can scuff and apply another coat. This means many days of build coats, just to get enough varnish down, to prevent sanding through and screwing up a stained surface. Epoxy can lock down the color with a few coats and the smoothing process can begin sooner.

Not everyone is comfortable with this. Traditional methods, using build coats, then smoothing coats of varnish, works just fine and has for centuries. New products are available, like water based stains, gels that seal and stain, materials that supposedly seal, stain and provide a finish all in one can are on the market. Then the urethanes which can offer a harder, clearer finish, that dries fast. These products have to be evaluated by you. None of us can tell you what is best, because we don't know what you're familiar with, all of us have our favorite stuff and methods.

For you, I would suggest you keep it simple and basic. Seal the wood with thinned varnish, then stain if you think you need it, but use one that is just a stain, not a "do all in one can" kind of product, then lots of coats of varnish, sanding very lightly at first, then progressively (after some bulk is down) trying to smooth out the final finish coats. The last coats will be wet sanded and applied as thin and as neat as possible.

The bottom line now is to keep the effects of the on coming winter from screwing with your boat. This way your efforts this spring will move you forward, not just repair what the winter has brought you, by way of damage.

If the mast is out of the boat, you can use this as a "ridge pole" down the centerline of the boat. Of course you'll want some saw horses or similar structure holding it up. A tarp can drape, tent style over this and make a nice little winter shelter. If it's still in the boat, you can use furring strips over saw horses to do the same thing with the mast sticking through the middle of it. Seal up around the mast as best as you can, because this will be a source for leaks.

 

Flumixt and PAR :
Both of you have offered great advice and I wanted to thank you for takingt the time to write in such helpful detail. As you can see, I'm obviously a novice at this......and have a big task ahead of me.

I'm going to have the hull sanded down in the next few weeks. Depending upon what I find - (supposedly there are some fiberglass or glassed over patches on the wood hull for whatever reason I don't know) - I may or may not be able to go natural with it. If the fiberglass interferes with the stained look (which i now understand to mean pigmented epoxy - a brilliant idea) then unfortunately I'm going to have to paint it white..... (unless anyone else has an idea on what to do with that - wood filler?)

so that's the case. Thanks so much for your help. I'll keep you posted.
The Sound