Varnishing woodwork on GRP boat

[cefnhoile]

I'm the new owner of a GP14 in GRP with wooden fittings, like the one shown at GP14 Sailing Dinghy. GRP with Road Trailer and Launching Trolley. | eBay

I have bought some Yacht varnish to maintain the woodwork but I am missing practical knowledge of how people approach the job.

For example, does it make sense to remove everything that can unscrew and varnish it far away from the GRP, or do people normally try to mask around the woodwork and leave it in place (especially given the age of the boat and the screw fixings.

What preparation of the wood should I attempt, especially in the case that I leave the fittings in place to varnish them I need to be careful not to damage the GRP while preparing the wood.

Thanks for any suggestions.

 

[Tranona]

Welcome.

Yes, Makes sense to mask off before preparation and during coating. Take it back to bare wood with perhaps a combination of chemical, heat scraping and sanding depending on how bad it is and what is on there already. Then degrease and follow the instructions for the varnish you are using (thinning, rubbing down between coats, number of coats etc).

 

[AndrewB]

Of course it all depends on how 'beautiful' you want your new dinghy to look. Personally, I would be more interested in sailing a seaworthy boat than in owning a showpiece, and my main aim would be to achieve a finish that lasts well, protects the woodwork, doesn't make the boat look like a disaster zone, and (perhaps) maintains its resale value.

So taking all the wood right off is over the top, unless you can see any rot. I would remove all fittings (as far as practical), then strip right back to bare wood. This can be done with coarse sandpaper but a combination of 'craftsman' chemical stripper and a skarsten type scraper is quicker. Sand off any previously exposed grey patches, or recolour if they are really bad. Fill any exposed deep grain. Then sand to a good smooth surface using 400 grit paper. (sanding well back should avoid the need to degrease). Be very careful not to go right through the outer ply of any plywood. Sand by hand if possible, or a really light touch with an orbital sander on large flat areas, but on no account use a disc sander - I wrecked the finish on my wooden GP14 that way!

You've already bought your varnish, but be aware there are quite different types available, some much more expensive than others but the best (two-part polyurethane) will last much longer. As Tranona says, follow the instructions, mask the GRP and any remaining fittings, but I would suggest if you are not experienced, put on coats really thinly to avoid runs. Four coats will give a decent if not perfectionist finish, lightly sanding in between.

 

[tidclacy]

If the varnish is in fair condition just give it a sand and give it 2/3 coats. No need to strip right back if ok.
What kind of varnish have you got at present. I always used Epiphanes until I discovered Le Tonkinois which I find far superior. Bare wood for good protection needs 8 coats whatever you put on.
Le Tonkinois

 

[cefnhoile]

Thanks for all the ideas! The varnish I bought is Sadolin Yacht Varnish - Clear - 750ml but I could take it back. I'd feel the task was much more approachable with the wood removed and I'd like to have a routine that's easy to repeat in a couple of years. Is there a worry about e.g. unscrewing seats or panels? I don't know what to expect. For example I could easily varnish undercover at home in my own time and not be concerned about weather, masking or climbing in the boat on the trailer at the sailing club.

 

[Alfie168]

For this season just lightly sand, mask off grp and make the woodwork sound with repair coats of varnish Then go sailing and enjoy the boat and save any in depth work until the end of the season. There is plenty of winter to do repairs and not enough summer to sail in.

I'd be wary of removing too much woodwork in any event unless you are a half decent woodworker. Hand sanding or orbital sanding....NEVER rotary sanding.

 

[cefnhoile]

Thanks, Alfie. Sounds like a plan! People in the thread sound doubtful about removing wood elements. What should I be worried about with removing wood pieces? Will they not screw back, or some other difficulty?

 

[Alfie168]

Thanks, Alfie. Sounds like a plan! People in the thread sound doubtful about removing wood elements. What should I be worried about with removing wood pieces? Will they not screw back, or some other difficulty?

It can become a "where do I stop" game which is why I suggest you save up major jobs until the end of the season. There is never less to do than you expect...it's always more. Screws can snap and then be a big problem to extract cleanly, joints can be difficult to remake neatly.
Planning time and thinking time is rarely wasted so I would decide what kind of finish standard you are seeking, and being blunt, what the boat merits in terms of time spent and outlay to achieve your aims.
You would normally leave woodwork in place for a revarnish unless there was a compelling reason to remove it e.g. if you were going to do a major refurb. I grew up on GPs and Enterprises and I think you have bought one of "the" great dinghies. They tend to get overlooked in the modern age but they have excellent build and sailing qualities. They will never attain much cash value, so just bear that in mind when spending your dosh.

 

[Tranona]

Once you have done your varnishing the best thing you can do for your boat is to fit an overall cover. If you have done a good job it will be years before you need to do it again. If, However you leave it exposed to the weather it will be an annual chore to keep it looking good.

 

[cefnhoile]

Its hugely valuable just to hear peoples common sense experience as I'm starting from nearly no knowledge at all. Having been concerned about a slow hull leak, needing a more practical trailer and aware of the value of spares I saw an identical boat for sale and bought that too so I may have quite a bit to do. I then found the reason for the leak in the first boat (loose bolts at centreboard washers) so I now probably have TWO serviceable GPs on my hands. Some differences in rigging which I can experiment with before I decide which to keep. One can probably be roller reefed (seems to have jib luff wire and spares for this) and has transom main, the other has hanks and a centre main. I suspect roller and transom main might be best if I can rig it but I have options.

 

[cefnhoile]

Forgot to say, both GPs came with serviceable boom-up covers.

 

[MADRIGAL]

I'm the new owner of a GP14 in GRP with wooden fittings, like the one shown at GP14 Sailing Dinghy. GRP with Road Trailer and Launching Trolley. | eBay


I have bought some Yacht varnish to maintain the woodwork but I am missing practical knowledge of how people approach the job.

For example, does it make sense to remove everything that can unscrew and varnish it far away from the GRP, or do people normally try to mask around the woodwork and leave it in place (especially given the age of the boat and the screw fixings.

What preparation of the wood should I attempt, especially in the case that I leave the fittings in place to varnish them I need to be careful not to damage the GRP while preparing the wood.

Thanks for any suggestions.

It is good to hear that you are planning to put that effort into a great older boat. Just because she's small does not mean she should not look great. The amount of effort and care that it takes to keep the brightwork looking fine is the sign of an enthusiast. That sort of person is also the type to renew fittings, replace worn lines and standing rigging, and yes, to check the seal on the centreboard pivot bolt and to do all the maintenance tasks that good seamanship requires. The great thing about a sailing dinghy is that everything is smaller and cheaper.

The problem with removing bits of wood is that you may have to do something to make the screws bite when you replace them. The advantage, of course, is not having to worry about the weather when you are doing your varnishing (6 to 9 coats). I've done it both ways, and now let the weather determine which approach I will take. The complete renewal of brightwork was a great indoor project during the first Covid lockdown. Fortunately, she was under a cover in my garden at the time, and so readily accessible.
Best of luck with your project!

 

[cefnhoile]

Thanks for more ideas and I learned a new word 'brightwork'. So getting screws back in might needs some Mastik or Milliput or something to remake the holes. The screws on the centreboard seat have been voluntarily unscrewing and catching on the straps of my buoyancy aid so might benefit from attention anyway. I suppose the seal of the seat screws into the flotation tanks is potentially important in a capsize. Also prizing off wood which has been varnished in place on gelcoat for many years might itself cause destruction. The prospect of planning six or nine coats while it is 25 miles from my home balanced on a trailer under a cover in a damp gravelly yard is quite a logistical challenge compared to topping up the coats in the cellar at home each morning/evening over just one working week between sailing weekends, but that does assume things will go back as easily as they went on, which is a gamble. To manage this in the season I might have to accept one of the GPs is in service mode and sail the other.

 

[Red]

Linseed Oil
After many years of varnishing I have switched to linseed oil it makes boat maintenance easy and passers by love the look and smell of the “varnish”. Apply liberally to raw wood so that it soaks in and occasionally go over it with a rag dabbed with linseed oil. The wood also has a better real wood feel which looks absolutely beautiful, and the smell wonderful. It is reasonably priced at less than £3 a half litre bottle and can also be applied when the weather is not so good.

 

[Tranona]

Much of the comment so far have assumed the use of conventional varnisher which do indeed require a lot of work to get looking good and staying that way. There is an alternative and that is to use a modern porous woodstain as commonly used on buildings, doors, window frames etc. Far superior in ease of application and longer lasting. Only downside is that they usually have tints and don't have a full gloss finish. in my experience the best of these is Sikkens Cetol HLS/No7 2 part system. I have used this on things as diverse as a 10m long Douglas Fir mast and the new barge boards on my house. Easy to apply, although 5 coats in total needed and expected minimum life of 10 years - the first lot I did on the house is now 6 years old and looks like new. However expensive and only available in larger tins so a bit OTT for small dinghy parts. An alternative aimed at the yacht market is International Woodskin which is a one part. I have used this for 20 odd years on teak, mahogany and iroko and find it easy to apply (3 coats) and long lasting. The first photo shows my previous wooden boat with the newly finished mast in Cetol and most of the wood trim is Woodskin which at the time of the photo was more than 10 years old and only minor refreshing, mostly on the horizontal surfaces. Second photo is my current boat. Trim is teak and Woodskin, approx 3 years old.

Having owned wooden boats all my life (the boat in the first photo from 1980 to 2019!) there is no way I would use conventional yacht varnishes again. Even the GRP boats had Woodskin on the wooden trim as in third photo.

 

[MADRIGAL]

Much of the comment so far have assumed the use of conventional varnisher which do indeed require a lot of work to get looking good and staying that way. There is an alternative and that is to use a modern porous woodstain as commonly used on buildings, doors, window frames etc. Far superior in ease of application and longer lasting. Only downside is that they usually have tints and don't have a full gloss finish. in my experience the best of these is Sikkens Cetol HLS/No7 2 part system. I have used this on things as diverse as a 10m long Douglas Fir mast and the new barge boards on my house. Easy to apply, although 5 coats in total needed and expected minimum life of 10 years - the first lot I did on the house is now 6 years old and looks like new. However expensive and only available in larger tins so a bit OTT for small dinghy parts. An alternative aimed at the yacht market is International Woodskin which is a one part. I have used this for 20 odd years on teak, mahogany and iroko and find it easy to apply (3 coats) and long lasting. The first photo shows my previous wooden boat with the newly finished mast in Cetol and most of the wood trim is Woodskin which at the time of the photo was more than 10 years old and only minor refreshing, mostly on the horizontal surfaces. Second photo is my current boat. Trim is teak and Woodskin, approx 3 years old.

Having owned wooden boats all my life (the boat in the first photo from 1980 to 2019!) there is no way I would use conventional yacht varnishes again. Even the GRP boats had Woodskin on the wooden trim as in third photo.

I like the sound of that. I'm going to try Woodskin on a new cockpit grating this year. I was concerned that varnish would not stand up underfoot.

 

[Tranona]

Woodskin is not very abrasion resistant as it is rather soft. If your grid is teak, best left bare. If not a durable wood then probably a 2 pot with added sand for grip might be the way to go.

 

[jwilson]

One person has recommended two pack varnish, on the absolutely correct grounds that it lasts longer. It does, but you really will curse for a long time when the day comes when you have to get it off, as sooner or later you will have to. If you want shiny, ordinary yacht varnish is pretty easy to get off again. I have spent a lot of time over many years of owning very pretty boats sanding and scraping and varnishing every winter/spring.

A dinghy with a good cover up should go 2-3 years at least between revarnishing. Your dinghy trim is probably some variant of mahogany, which needs protection of some sort as it is not that rot resistant, unlike teak or iroko. Oil will protect it, but it attracts dirt and the wood steadily gets darker.

Personally I'm not a fan of Woodskin type finishes: I like the gloss look on external brightwork but satin on interior. My present boat (as a deliberate choice) has zero varnishwork on deck! My previous one was plastered with varnished teak and bronze fittings.

 

[Stemar]

+1 for le Tonkinois. You need to get back to bare wood, which can be hard work, but the next time, you won't have to as it doesn't crack and let water in like ordinary varnish. Just a quick rub down and and a few more coats.

One thought, though. That rubbing strake round the outside is going to get battered in normal life, If it's going to look good with any sort of varnish, you'll be refinishing with monotonous regularity. Is that what you want to do with your time? If not, get some stuff from B&Q for patio furniture, wipe on a couple of coats and go sailing.

 

[MADRIGAL]

Woodskin is not very abrasion resistant as it is rather soft. If your grid is teak, best left bare. If not a durable wood then probably a 2 pot with added sand for grip might be the way to go.

Thanks for that advice. Two-pot varnish was my original choice. I am also considering two coats of clear epoxy with Epihanes varnish on top for UV protection, as some have suggested at different times on the forum. The OP should now have plenty of options to chose from.