Mirror Dinghy: Correct Paint System ?

[Ady Stokes]

Hi everyone, I am hopeful that someone may be able to help me with the following:

I have recently purchased a Mirror dinghy, which was built in 1970. Some of the paint is flaking on the hull and likewise small areas of varnish are becoming detached from the gunwhales. I intend to repaint and revarnish the areas in question, but after having scoured the internet for advice/guidance, I am now more confused than when I started. The advice seems to be confusing insomuch it appears to be written by people in the know, for people in the know, and not for the layman such as myself. With regards to the hull, do I apply resin, epoxy, primer, one part paint or two part paint ? And how do I prepare ? I would assume sand down and remove loose paint. Likewise, what preparation for the varnish would be required; totally remove or just sand, and what type of varnish and how many coats are required ?? If someone could either point me in the direction of a good book which contains answers to the above or give me some guidance, it would be very much appreciated. Many thanks..

 

[john_morris_uk]

One answer is how long is a piece of string?

In simple terms - and if you just want to smarten the dinghy up, sand back any loose paint until you have a good key and give the hull a couple of coats of marine paint. You might get away with exterior grade gloss, but I don't think you will save very much money - especially if you shop around for the marine paint. I usually try and remove all the fittings when I am repainting a dinghy; it looks much better when you put themback on over the fresh paint.

For the varnish, you might get away with sanding back and putting another coat or two on, but if the varnish is poor, the only real answer is to strip it all off and start again. There's no short cut to good 'brightwork' which is the fancy name for varnishing, but for a slightly elderly mirror you are probably not looking for a mirror pardon the pun) finish. You can get away with a can of nitromors, lots of scraping etc, neutralise according to the instructions and lots of sanding to get a good smooth surface. You might need some wood bleach if there is a lot of fading and variation of colour and some wood stain if you want to be fancy. You then apply SEVERAL COATS of varnish. Good varnish isn't cheap - and if you are going to use it on the sea, don't use the stuff from B&Q - even if its called yacht varnish! Epivanes or International etc all make good varnish and no doubt some other forumites will be along to say that their's is best. Traditionally you need six of seven coats, but I wouldn't worry after the first three or four. You aren't trying to win a concours - just trying to protect the wood.

Top tip: if you remove the fittings, dip the screws in varnish when you refit them as that will stop water getting under the varnish and producing patches of discoloured wood round the fittings.

Some more tips. Blue masking tape is worth the extra money. It comes off after a week or two. Preparation is 90% of the job. The painting is the easy bit. don't know of a good book - try the International Paints web site?

 

[Ady Stokes]

Hi John,

Thanks for the reply for which I am very grateful. With regards to the marine paint, I am having problems identifying exactly what marine paint I should be applying to the hull of the boat and am unable to find and identify a satisfactory paint system after reading the various literature from companies such as International, Jotun etc. I would assume that I need a primer, however, I can't find a paint that will go on top of the primer that is suitable for underwater use, apart from antifouling, which, as the boat will be used primarily in fresh water, albeit with limited sea use, I don't think I need. If you have any further thoughts/information, I would be again, most grateful. Many thanks, Ady.

 

[Alfie168]

The primer depends on the topcoat you decide on, but for a single pack finish any good quality wood primer for external use will be sufficient as its only purpose is to stop the topcoats from being absorbed into the wood.

Then your choice is 1) Single pack polyurethane enamel or 2) 2 pack epoxy

The enamel is easier to use and repair, but not as hard as epoxy. On a boat as old as your I'd stick with enamel, and repair dings temporarily ASAP. Painting with enamel is more of a pleasure, painting with 2 pack means you have to have better temp control and limited time before the paint cures on you. It can be fraught until you get the hang of its behaviour and characteristics.

I found when repairing an ancient Enterprise dinghy was that if the ply had any soft areas from damp ingress then it was difficult to get any paint to stick and it would flake off anyway.

Extra time spent preparing the surface before painting is always well rewarded. You can't get a good paint finish on a poor substrate.

I had two Ents, one with Enamel and one with 2 part Epoxy so I've done it both ways as it were.

No need for anti foul unless its left afloat in salt water.

For single pack polyurethane the International product are 1) Single Pack Primer 2) Toplac for top coat, For 2 pack polyurethane us 1) Perfection Primer 2) Perfection Top Coat.

Other manufacturers will have parallel products. To be honest I'd be tempted just to use good quality external domestic paints such as dulux (don't go for own brand supermarklet cheapies they are poor quality). I'd sand back as far as your patience will allow with the hull, and any poor looking varnish I'd strip and revarnish (dont use peel off strippers with caustic in them..just nitromors and scraper), unless there is water damage to the ply, in which case I'd seriously consider painting that as well as there is limited aesthetic value in putting good varnish over a poor base. It just depends on what you have to work with, what level of finish you are aiming at, and how much you want to spend, and how much time you have. There is a balance to be had somewhere between effort and finish.

Tim

 

[Kwik Decision]

I concur with most, if not all of the advice given, particularly about preparation!

One pack Yacht enamal is fine for the hull of a dinghy which will spend most of its time sat on a trolly. 2 pack paints are more expensive and harder to use, and in my opinion not worth the cost or hastle. Years ago I did a similar job to you on an old plywood Scorpion, and used International 1 pack paint / varnish, which gave a very good finish. As Tim says, Toplac is internationals current 1 pack yacht enamal. I've used this recently, and got a very good finish, but it is quite pricy.

Hemple (used to be Blakes) do a similar range of boat paints, and I've heard good things about them, but they are also quite expensive.

When painting the floorboards inside, please use a non slip deck paint (or add some non slip additive to the paint / varnish before applying to the floorboards). I once cracked a bouyancy tank in a mirror when I was sea scouts, when my feet slipped on the gloss varnished floor boards as the boat healed over.

 

[Tranona]

You have two basic choices depending on the condition of the boat and existing paint and the amount of time you are prepared to spend. If the existing finish is very poor and falling off, then strip it back to bare wood and start again. The simplest and cheapest way is to follow the instructions from the manufacturer. So, with International, it is primer, undercoat and top coat. Toplac is more than adequate. You don't have to allow for underwater finishes unless the boat is permanently afloat and anti fouled.

If the current finish is basically sound, rub it back, removing any flaking paint. Re-prime bare patches, level off any bumpy bits with filler, undercoat and top coat. Stick with conventional one packs as two packs need more skill to get right and won't go over one packs. Toplac will give you an excellent finish and typically lasts 5 years before you need to do anything else.

Brightwork needs a bit more care as it is difficult to get a good finish without a lot of work. Taking back to bare wood is best. You can then build up with conventional varnish or use one of the modern permeable stains such as Sikkens.

Whatever you do, your best investment will be a cover for when the boat is not in use (95%+ of its life) to keep the elements off your lovely paintwork.

 

[Skysail]

We had a Mirror for a few years and it gave many hours of fun, including 'Wildcat Island' of Swallows and Amazons fame on Coniston - where we found 5 Mirrors ahead of us!

I restored it when we acquired it; I used one pack International paint, primer, undercoat and finish. Interior was varnished. Two pack is

a) expensive
b) not good on flexible surfaces such as Mirror panels.
c) difficult to sand and refinish later

Make sure you seal the gunwhales well with a few more coats, the upper surface is susceptible to water ingress and rot.

As Tranona said, if left outside a good cover is vital, get canvas rather than plastic, but anything is much better than nothing.

 

[Alfie168]

From our very own forum no less

http://www.ybw.com/forums/showthread.php?t=232781

Dulux Weathershield Exterior Gloss gets a lot of votes, but not the stuff they mix in front of your eyes. Its got to be factory stuff.

Tim

 

[Vara]

When I last tarted up a second hand mirror dinghy (26 years ago IIRC).

I bought the cheapest gloss and varnish from woolies, (now I spose Wilkinsons would be the shop of choice), the finish lasted for 10 years till I sold it at a handsome profit.

Apart from the preparation which has been covered, keeping it in a covered dinghy store away from damp and UV certainly added longevity to finish.

 

[electrosys]

Having got myself into the same situation last autumn, I would suggest first deciding whether you intend to fully restore the dinghy to it's former glory, or whether it's to be a 'tidy-up' job, and get yourself out onto the water a.s.a.p.

If it's the former, then by all means invest in the best marine paint. But if, like me, 'good enough' is all that's required, then use a quality household paint instead. Like someone has already said, avoid B&Q products, they really are sub-standard - pop down to your local tradesmen's outlet instead - I find Johnson's paint pretty good stuff, although Dulux Trade and Leyland's Paints also seem ok.

 

[VicS]

When I built my Mirror in the 1970s I bought a paint kit from International Yachtpaint

For the outside it consisted of International's "Metallic Pink primer" for wood and a single pack polyurethane yatchpaint.
( no undercoat as far as I recall)

IIRC the first coat of primer was applied thinned with white spirit followed by an un-thinned coat and the several coats of the finishing paint.
Rubbing down between coats in the normal way.

Modern equivalents would be International Yachtprimer and Toplac.
I'd also suggest an undercoat such as International Pre-Kote

A single pack polyurethane varnish was supplied for the inside.
The modern equivalent would be International Compass. I'd suggest up to 6 coats.

What you must not do is put a 2pack paint or varnish on top of a single pack system.


To be honest although I would use a varnish from a proper yachtpaint supplier ....NOT a yacht varnish from a DIY store as they are rubbish, I would use a good quality domestic undercoat and gloss eg Dulux , for the outside.

In fact for my wooden dinghies ( including the Mirror) I still use an International single pack polyurethane varnish for the inside and Dulux for the outside.

Internationals "Boat Painting Guide" Might be worth looking at http://www.yachtpaint.com/LiteratureCentre/1726 BPG 09_79 Page_Online_UK.pdf

See also the product data sheets for whatever you decide to use and follow the procedures detailed.

 

[Lakesailor]

Everyone has the right idea.
Don't get involved in a major rebuild. (been there, etc..) Have a look at my Heron rebuild (like a Mirror but with a pointy bit at the front.
Do be careful that you have spotted the areas which may have some rot. It hides under the paint.
I used Blakes primer and Yacht Enamel, although it's called something else now and I found it a bit soft . Someone mentioned Johnson's Paints, and they are very good. I've used them quite a bit on tenders and such.
I would not use a wood stain under varnish. Damage is then just so difficult to make good. I wouldn't use an epoxy coating inside a plywood boat either as there is a risk you may trap moisture in the ply. At least if it's just paint or varnish it will blow off if the wood is damp.
If you do find soft plywood decide if you would prefer to replace or repair. It's often easier to replace it. If you want to repair don't use ordinary fillers. Whatever you use needs to be epoxy-based. But if you don't need to do that, don't even go there.

Wow. I've just looked through those rebuild pics again. If yours looks anything like my before pics, put a match to it. Never again.

 

[saltylegs]

I can remember my dad building me a mirror from a kit about 35 years ago and kit was ordered with the paint this was single pack International and was applied 2 coats pink primer, 2 undercoat and 2 gloss (Albatross blue).
I bought one for my boys 2 years ago and it was of the same vintage it was a real barn find that had been stored for a long time and was in good nick but the wood was very dry.
As a result I was able to remove all the paint back to the primer with a flat wallpaper scrapper, to my suprise it all looked original and appeared to be 2 coats of each as described above but in yellow and had been on there for over 30 years so single pack seems to do the job.