Varnish a new bowsprit

[dmksails]

I'm having a new bowsprit made. It's over 6-ft long and is being made from sepele.

Prior to putting it back on board I will have it in the garage where I'll but a finish on it. Here's the question - Do I varnish all sides at once, or do the top half, then spin it and do the bottom.

The reason I ask is that the spar is long, heavy and awkward to deal with. Any suggestions?

[TedCG1]

Hang it vertically from the ceiling.

[JPA Cate]

Hang it vertically, and spray it, if you have an airless sprayer. You can really get an amazing finish...but don't bother if it would be your first time. It does take practice.

Ann

[tkeithlu]

....and don't skimp on any part of the job - it's going to be exposed to a bunch of salt water.

[gonesail]

if brushing it is much easier to have a level surface. do the top and then the bottom.

[Alan Mighty]

Originally Posted by dmksails

The reason I ask is that the spar is long, heavy and awkward to deal with. Any suggestions?

That's a fairly long wooden bowsprit.

I'm guessing that you chose vertical grain (grain in line with the length of the bowsprit) and you sliced your sapele and then laminated it to deal with tension within the timber.

One important item to know is where your gammon iron will sit. From the gammon inboard, your bowsprit will be purely under compression.

The important part is of course the rest: from the gammon outboard.

You will likely have bowsprit shrouds to limit yawing movement, and a bobstay and headstay to limit heave and set of the tip of the bowsprit. Nevertheless, such movement will take place.

Were you to sit on your bowsprit while sailing to weather, regardless of the tension in bobstay, bowsprit shrouds, etc you will feel movement.

That movement translates to relative movement between lamina.

Your job therefore is to cover the lamination joins (and not just each lamina) with a flexible coating that will remain flexible and resist cracking as it ages (and deal with both relative movement and UV).

Should your brightwork coating crack, usually along or associated with a lamination join, water (and you are really most concerned with freshwater/rainwater and not salt water) will slide through the crack and sit between your brightwork coating and the timber.

Robust use of penetrating epoxy is one solution.

An older solution, used by working craft not recreational showpieces, was not to coat the bowsprit with a hard coat that would crack, but instead routinely to coat bowsprit and other spars with petroleum jelly or some other potion that shed water.

The critical zone is not far forward of where the gammon will sit.

Think of your bowsprit as an unwilling lever (unwilling because of the bowsprit shrouds, bobstay, and headstay).

Now think where along the bowsprit the torque from the tip will be toughest. And where, regardless of the dimensions of your bowsprit, bending is likely to occur. It's seldom at the gammon and more likely some small distance forward.

That's where you have to concentrate your efforts.

[Alan Mighty]

Further, I suggest you make a boat canvas cover for your bowsprit. And cover your bowsprit when in port.

Light colour is good, even though darker boat canvas tends to survive a tad longer than light. What glue did you use to laminate the sapele?

Not a few glues have a deflection temperature, low enough to be reached by hours in sun, at which the glue loses some part of its strength.

The more you cover your bowsprit, the less the UV damage of your brightwork coating. The less the UV damage, the more likely your brightwork will retain some degree of flexibility and integrity.

And in general terms, a cooler glue line is better than a hot one.

[dmksails]

Alan - thanks for the great info! What do you think of using an oil finish instead of varnish for the spar? On my other brightwork I'm using a boat sauce recipe of part oil, part varnish I received from the local boatbuilding school.

[Manateeman]

Built a 6’ 6” bowsprit out of clear vertical grain Douglas fir. Two feet on deck, four feet beyond stem. Four piece laminated in epoxy and covered in epoxy then Minwax Helmsman varnish. Gammon iron from Lyle Hess. Anchor roller pin did not go through the spar, but under it in custom bronze fixture. Extra ring and bronze star at tip.
A hurricane took the rig down. We believe the bowsprit nosed under the anchor chain between the mooring ball and the stem.
I put a 1/2” teak pad under the spar aft of the stem. Two 3/8” bronze plates cross the spar thru bolted with four 1/2” bronze bolts each plate. Never saw a crack in the varnish from flex nor any signs of water damage. Rounded the heel and put a 3/4 “ solid bronze bar through parallel to the deck for the mooring eye. Worked perfectly for years till she lost to a hurricane. No other damage to the boat as mast was deck stepped.
Just loved having four feet forward of the stem. Wish I had made it five or six.
I made another bowsprit from a single piece of clear old growth Douglas fir which came on a special railroad car. One of a number of support logs for the mast of the US Constitution when they did her main mast in Boston. Very beautiful wood.
Happy trails to you.
Captain Mark

[valhalla360]

Varnish, Cetol or other surface coatings...expect to sand and redo it every 6 months if you want it to stay pretty. If you still proceed, it will look better if you can do each coat all in one go but if it's not practical, it's not a big issue.

Oil will still need regular updates but it's less fussy so long as you keep up on it.

[s/v Jedi]

You will need to seal the wood. Traditionally this is done by thinning the same product used for final finish (oil, varnish etc.) by 50%. There are specialized sealer products now, but I would skip all that and go for the much superior penetrating epoxy instead.

I agree with others to hang it up vertically and brush from top to bottom.

I use TotalBoat Penetrating Epoxy and after mixing it (it is 2:1), I reduce it 40-50% with denatured alcohol, then brush it on with a 3” disposable chip brush.
When you see dry spots appearing, go back and add a bit then continue until the whole sprit is done.

After a 24 hour cure, sand the epoxy back to the wood fibers using 220 grit. It now looks like it was before, a little darker and much harder. Now you can finish with varnish or similar product. I used Epifanes varnish successfully over this epoxy.

[CarinaPDX]

What does your krantz iron look like? My original one was a cap (i.e. closed at the end) and resulted in trapped moisture and eventual rot in the CVG Doug fir sprit. The old designs where the wood extends through the krantz iron are far preferable. Usually these are slightly conical and the wood is tapered to match, with a shoulder to stop the krantz iron moving further. If you don't have one like this then now is the time to upgrade.

I think you have had some good recommendations. While just starting with thinned varnish (Cetol is my preference) and building works well I think Jedi's recommendation is probably the best approach, with penetrating epoxy. Originally I coated the sprit with epoxy under classic varnish, which held up well but when it eventually failed it was a PITA to remove, so I would stick with just saturation with penetrating epoxy and then coating of choice, or thinned coating. I like Cetol because it is durable, easy to overcoat (no sanding), and easy to repair. It looks like varnish because I only use two coats of pigmented Cetol then only use clear Cetol for all succeeding coats (using only pigmented coats creates a strange orange effect). Unless you are expert at it I would not spray on the varnish; modern varnishes level very well after brushing. Personally I would varnish with the sprit horizontal, supported at spots that will be hidden when installed, and patched later.

Greg

[bailsout]

I only use Smith’s penetrating epoxy. No need to thin, really penetrates.