Replacing wooden gunwales

[geoffr]

Hi all:

In an earlier post I indicated I was finally getting around to replacing the wooden gunwales on QUMBU.

I had toyed briefly with using a metal edge strip (as others had done), but I wanted to retain the maritime 'look' of the original design, and so have chosen to go with wood again.

I've just about finished the job, and have learnt a lot (some of it the hard way). As an indication, the first gunwale took just about all day, whereas the second one took about 2.5 hours!

I've taken a series of pics along the way, and will post them here for others who might need some guidance if they choose to do a similar job.

The gunwales I replaced were the originals, so they have done very well. However, dry rot and a few hard knocks (by previous owners, I hasten to add) had taken their toll, and it was well time to replace these rails -- particularly the starboard side.

You can see the damage in the first pics below; I'll add more through this week, and would welcome feedback.

Cheers,

[geoffr]

Hi again:

The only way I could remove each gunwale was with a broad sharp chisel and a rubber mallet.

When the original gunwales were attached, they used glue as well as bolts to secure them.

The bolts and nuts had long since seized, so even once I prised off their wooden cover plugs, it was impossible to unscrew these -- especially with a flat-blade screw driver.

So I left the bolts there and just hacked away the wood around them. Then once all the wood was removed, I cut each bolt off with an angle grinder, leaving each fibreglass rough edge ready for sanding, re-sealing and other preparation, prior to installing my new wooden edges.

Cheers,

[Mark]

Geoff

Terrific, just what I need to get started but I will let you finish first.

BTW in the second pic I spy a blue bow roller addition, can you take a pic of that and tell me what you have done there? I find the original bow roller setup entirely inadequate for my anchor deployment. I think you may have the answer.

Cheer and thanks

mark

[geoffr]

Thanks for your interest Mark!

I'll post separately re my bow roller.

I attach here some pics of my wooden gunwale rails, before and after treating with wood oil.

A trusted source recommended I use Queensland Spotted Gum for these rails, as that timber is easy and flexible to use, yet has great water resistance -- especially to sea water.

I order two 6 metre lengths and had them routed to the exact profile as my old gunwales. The work was done by Belmont Timber (Geelong) and delivered to my door, for a total of $300 -- which I thought was pretty good. They also tossed in some scrap from which I have routed my bolt hole covers -- more on that in a later post.

I decided on wood oil (designed for treating timber decking) rather than marine gloss varnish (as I had done previously), because my trusted source said the oil would last better, and require less maintenance (compared to sanding and revarnishing every year or so). Time will tell!

You can view a range of different wood oils at your local hardware store. I was a bit perplexed, so just chose the cheapest of reasonable quality, which turned out to be Australian produced. If you read the labels, they all seem to contain much the same ingredients and do the same job, yet some are more than twice the price. I figure if this oil is not much chop, I'll just buy dearer stuff next time and lay it on over.

The oil went on easy enough with a brush, and turned the gum a deep mahogany colour. Two coats took several days to soak in fully. I chose warm, dry days to do this work back In February.

In my next post I'll start the installation.

Cheers,

[atles]

very nice !! well done

[geoffr]

Hi again all:

We've now reached the tricky part of replacing the wooden gunwales: measuring and cutting the angles on each rail where they almost meet at the bow plate.

To measure this angle, I laid an adjustable square along the end chord of the hull curve, closest to the bow plate on the deck.

I then transferred this angle onto my wooden lengths, and cut the angles using a relatively fine toothed bench saw.

I checked the angles for fit by laying them in place onto the hull edge, with the other end of the (unbent) wooden rail supported in a G-clamp, clamped onto a step ladder -- to keep the rail in the same horizontal plane as the deck.

Hopefully the pics below show what I'm talking about.

Finally, I used a wood file to adjust the angles slightly, and also to remove any sharp edges.

The rails are now ready for fixing to the hull edge (see my next post).

Cheers,

[geoffr]

Hi again:

With the end angles cut for each gunwale rail (using a fine tenon saw, and finishing off with a file and sand paper), my next task in replacing my gunwales was to secure the bow end of the first (port) rail with a bolt and nut.

I chose to try and reuse the existing holes along each edge of the boat deck edge. I soon discovered though that if I tried to drill up through these holes into the gunwale rail, I couldn't get my powerdrill in close enough to the hull to put the bit up and out through the centre of the wooden rail. Instead, you end up almost drilling through the inner side of each rail -- which is not ideal!

So, to overcome this challenge, I drilled from the top down through the wooden rails, at an angle, toward the hull and through the existing holes in the fibreglass deck edge. This worked well once I got the hang of it.

I chose to use SS 3/16 inch diameter bolts, with an 8mm diameter round head and flat driver fit. On each bolt I fitted a SS washer up against the underneath fibreglass edge, then a nyloc hex nut.

The process was: drill the main body hole right through the wooden rail from the top and down into the existing (old) hole in the deck, using a 3/16 high speed bit. Then again from the top, I used an 8mm flat paddle wood bit to sink a hole 8mm in diameter and 10mm deep into the wooden rail.

Some of the old holes under the fibreglass deck edge were lumpy or too thick, so I used a half-inch paddle bit to slightly countersink under there, to thus allow the SS washer and nyloc bolt to tighten up nicely.

Once I got the first two bow end bolts and nuts fixed, it was just a methodical process from there to work my way to the stern, gently bending the rail as it sat supported on my step ladder out to the side.

Toward the stern I began using my G-clamps to pull the rail in as tight as possible against the edge.

The spotted gum had sufficient flex to easily make the bend right around the hull without needing to be steamed or formed in any other way.

The port rail took over three hours to complete, which included learning how the hell to do it! When I did the starboard rail the next day, it took me half the time.

I did not bother to use glue or sealer (as they did originally); it would have made it a two person job, and been pretty damn messy.

More to come!

Cheers, Geoff

[geoffr]

Hi again all:

I'll finish this thread with the final task: cutting the bolt cover plugs and fixing them in place.

As I mentioned previously, each bolt hole is 8mm in diameter; so, you need to cut out 8mm diameter plugs from the same type of wood to plug each hole. My friend Jim used his pedestal drill and an 8mm hole cutting bit/tool to drill out about 50 plugs for me into a flat piece of 25mm thick Queensland spotted gum that I had ordered with my routed rails (the timber supplier threw this in for free).

Each plug is drilled to about 20mm in depth, but each finished plug only needs to sit about 8-10mm down into each hole. You remove the plugs from the scrap timber by gently prising them out, one at a time, with a flat-blade screwdriver.

Each plug is a VERY tight fit in the holes along the rails, so you need to sand (or file) each one around its circumference until it fits snugly into the top of its intended hole. You then smear a little two-part epoxy glue (Araldite, etc) around each plug, prior to tapping it down into its hole. Use epoxy rather than PVA - as the latter is water-based and would not last in sea-water.

And as Jim reminded me: you don't just fill the hole with glue, because if I ever want to replace a bolt in the future, it's much easier to get it undone if it's not caked in glue.

Once each plug is hammered home, it will protrude about 8-10mm from the hole. Just leave this protrusion until the glue firmly sets (i.e. come back the next sunny day), then gently remove each protruding plug top with a sharp chisel (and mallet), levelling each one smooth with the top of the rail. Once all are cut level, sand them off to be smooth with the rail, then give the entire rail (and plugs) another coat of oil, and allow to dry.

On my rails, this whole process worked pretty well -- though a few plugs shattered and I had to redo them (so cut a few extra plugs).

I'm very happy with the finished look (dark wood along each side of the boat), but it does clash a bit now with my two wooden cabin top grab rails (which are light marine varnish over 25mm diameter dowell). So my next job will be to replace these rails with new dowell, bolted and plugged in the same manner, but coated with stain and oil this time to match the new gunwales.

That's it; if you have any questions or comments, send them through.

Cheers,

[Mark]

Hi Geoff

Thanks to your instructional posts I have this week embarked on toe-rail replacement pretty much in line with your own procedure. I have been unable to get 6m lengths of timber so settled for smaller lengths with a planned mitre join towards in the straighter part of the rail towards the stern to make the full length.

I bought Tassie Oak, my friend who was a woodworker in past lives and now importantly a sailor, milled the timber and rout it to shape yesterday.

I am using a different approach to wood protection. I am going to use Tung Oil which I have found superior for protecting marine exposed wood, (again a referral from my friend). Yesterday after milling I brought the timber home, sanded it and then primed using Endeavour Marine priming oil (made from natural oils as I read) and I now letting it cure and harden/dry for the requisite 3 days, prior to the application of Tung Oil.

I will post pics as I process this as I think others might find this a better means of timber protection than varnish or paint. I have tried decking oil previously but always need to recoat after a few months. Tung oil penetrates the timber forming a water impervious layer and the outer surface of the wood eventually forms a hard layer. The Chinese have been using it for thousands of yrs apparently for water protection of wooden boats.

So thats the update. The other thing I a going to do differently is use rounds headed SS screws but not recess them with plugs as you did instead they will sit on top of the timber. I think they will look quite nice actually. We will see.

Cheers

Mark

[Ozzie]

I used deck oil on my handrails and storm boards last year Mark and I was recoating quite often . How much were the primer and tung oils and are they readily available? Might give it a go this haulout.

Edit just looking Bunnys sell tung oil. Feast Watson also make one . No mention about the priming first in the Wikipedia stuff on tung oil. I assume your mate suggested this .