How To Remove Antifouling

Disclaimer: This post is intended as a guide.

As we come to the end of the sailing season, it’s time to consider laying up your boat for the winter and one aspect of this is removing the antifoul from your boat if it is in poor condition.

Now, opinions are split on when is best to strip the old antifoul. Some people will wait until next year when they bring their boat out to apply fresh antifoul. However, there is a train of thought that suggests doing it now could save in time and effort in the lead up to the season next year as the old antifoul is still soft and easier to strip.

We briefly covered how to remove antifouling in our Antifouling FAQs post earlier this year but we have now expanded on this topic further with its own dedicated blog post.

Read on to find out how best to remove antifoul from your boat.

1. Prioritise Health & Safety.

It’s extremely important before you begin this type of work to ensure you are wearing the correct protective gear. This includes safety goggles, nitrile rubber gloves, overalls, and a solvent mask (if working in a confined space).


It is also highly recommended that you work in an area that is sufficiently ventilated.

Although it is more focused on applying rather than removing, it is worth keeping in mind this handy leaflet created by The British Coatings Federation (BCF) to “inform and educate boat owners with regard to the hazards associated with antifouling their boats.”

2. Remove loose antifouling.

Whether the boat has just come out of the water or it has just come out of storage, you’ll want to begin by removing any loose antifouling with a high-pressure fresh-water washer.

Make sure that any residue and wash water is contained during this process and disposed of appropriately afterwards. Once this has been completed, mask off all areas that will be stripped.

3. Use an antifouling stripper.


To remove old antifouling, you can use a paint stripper like International’s Interstrip AF. These products have been specially formulated to remove antifouling from all substrates and Interstrip, in particular, won’t harm the gelcoat when used on glass fibre.

Application of the paint stripper should be generous and with an old brush. Ensure you follow further application guidelines provided on the product label.

You should leave the product to work for a minimum of 10 minutes, though the time required will depend on the temperature and the amount of old antifouling on the hull.

4. Remove old antifoul.

Once the appropriate amount of time for the stripper has passed, take off the old antifoul with a blunt scraper while it is still soft. Ensure the product does not dry out by working on small areas at a time.

Interstrip is able to remove several coats of antifoul in one go but heavy build-up might require this step to be repeated several times.

Final Note: Remember that you will need to sand and prime the hull before applying fresh antifouling.

N.B. Due to the strict carriage of dangerous goods regulations, Gael Force can only dispatch antifouling and associated products to addresses on the UK Mainland.

The DIY Restoration of a Small Yacht: Rudder Surgery (Part 2) & ‘Bringing Her Home’ (#5)

seb-profile-photo-ytSeb, originally from Portsmouth in Hampshire, is the Sales Supervisor for the Gael Force Marine Megastore in Inverness.

He has agreed to write a series of posts following him and the restoration of his 26 foot, 54-year-old fibreglass yacht.

This series of blog posts so far can be read here.

Estimated reading time: 8 minutes.

BLOG POST #5: Rudder Surgery (Part 2) & ‘Bringing Her Home’

Before we get back to the rudder, there’s the small matter of transporting the boat overland to her new home – my driveway!

I moved house last month (hence the lack of an August blog entry) and before all the boxes were unpacked, I was organising transport for Sunfire to take her overland from Hopeman harbour to a nice little spot just outside my front door.

The Invicta 26 isn’t a particularly large or heavy yacht, but my nerves were still shot as I helplessly watched her suspended several metres in the air, cradle and all.


Getting to this somewhat precarious point took a couple of hours – we had to shift her around in the cradle and adjust all the side supports before lifting her.

There were a couple of touch and go moments – at one point I think most of her weight was on the side supports – but ultimately we got her on the lorry without any damage other than some frayed nerves and I was delighted to see her arrive safely at the other end.


Sunfire weighs about two and a half metric tons, which incidentally is the limit of the lorry’s crane when fully extended.  The shape of the driveway meant that the boat had to be craned off the back of the lorry, as opposed to side-on, which required the crane to be… fully extended.

It was a cool and overcast day, so when I saw a bead of sweat appear on the crane operator’s brow I knew it was the ‘maximum load’ alarms and not the weather that was making him sweat.

In the end, the crane held strong and the boat was carefully positioned into the perfect spot. When I look out my bedroom window I can now see Sunfire lying comfortably in her new home!


Now, back to the rudder.

Recapping quickly, in my last blog we saw how I cut out a huge section of the side of my yacht’s rudder with reckless abandon. The reasoning behind this was that I’d discovered that the entire thing was completely hollow and would fill up with water as soon as it was submerged.

I wanted to fill it with a rigid, closed cell polyurethane foam to add stiffness, strength and to reduce the volume of water that would ingress into it once back in the water. Making that first cut was one of those ‘no turning back now’ moments, but after discovering what lay inside, I’m confident it was the right thing to do.

There were lumps of what appeared to be old, rotten core material inside and a thin layer of powdery stuff covering all the inner surfaces. It may sound strange, but these little lumps of crud actually made me very happy as they implied that many years ago there was indeed a foam core in this rudder.

There was also glassed-in plywood around where the pintles were, which would have been for re-enforcement but was now completely rotten.


As always before attempting any repair, the first thing was to remove all the rot and clean all the surfaces.

Removing that rotten plywood was no easy task. I tried using a rotary tool with a small grinding attachment to grind it out, but the wood was so saturated (even after two years ashore) that it didn’t work. In the end, a good old chisel was the most effective.

With the rotten wood removed and the surfaces cleaned up I was finally ready to start rebuilding. Roll out the epoxy!


Epoxy is a very versatile substance and can be mixed/thickened with a variety of additives and powders in order to change its properties to suit any particular application.

West System has a range of epoxy products that will cover just about every kind of repair you can think of on a fibreglass boat. It’s also used for many bonding and re-enforcing applications on GRP or wooden boats.

I contemplated going into great detail about all the different epoxy products and how to use them, but that would itself span several blog posts and there are tons of helpful how-to manuals already available on West System’s website.

It’s important to note that whenever using epoxy, gloves and protective eyewear should be worn. You really don’t want this stuff on your skin!

Before I could think about putting in the new foam core, I needed to re-enforce the area where I’d removed the rotten plywood.

To do this, I wanted to fill the area with thickened epoxy and new plywood. I first cleaned the entire area with acetone and then coated it with a thin layer of un-thickened epoxy. The next batch of epoxy was thickened with 402 milled glass fibres and squeezed into all the nooks and crannies of the cavity.


I filled the entire void like this, adding in some plywood to bulk it out, and then glassed over the top to the repair with biaxial glass cloth to finish it off. I’m confident that it’s now stronger than it was and also that any points of water ingress around that area have been blocked up.

After this, I applied a thin mix of epoxy and 404 high-density filler along all the inside seams of the rudder, where the two halves were originally bonded together, to seal up any potential leaks.

This probably wasn’t necessary, but with the innards of the rudder so exposed, it was an opportunity I couldn’t pass up. The thinness of the mix allowed it to self-settle along the seams.


With the epoxy all fully cured and any amine blush (a waxy substance that forms on the surface as part of the epoxy curing process) washed away, I was ready to start pouring in the new foam core.

The two-part polyurethane foam I used was designed for this purpose and is much more rigid than the ‘builders’ expanding foam you get in a spray can.

The two parts must be mixed together at exactly the correct ratio – I used some electronic weighing scales – and when combined you only have a few seconds before the reaction starts. If you don’t pour the mixture quickly enough you’ll soon have a foamy disaster on your hands, literally! Again – gloves and eyewear should definitely be worn.

I started by pouring the foam in all the edges of the rudder then set about building it up in the middle.


The great thing about this foam is that it’s easy to work after it has cured. It didn’t take me long to cut and then sand it to a profile I was happy with. I bevelled the edge around the cut-out to give a good surface area for the new sheets of glass to bond with.

West System recommend a bevel of twelve times the thickness of the laminate you’re working on. In my case, the laminate was 4mm thick so I made a bevel of 50mm.


I was using a heavy tri-axial cloth for rebuilding the side of the rudder and I calculated that 4 sheets would give me the correct final laminate thickness.

The first sheet would be the largest – going slightly beyond the outside edge of the bevel and the last sheet would be the same size as the hole I cut out. I used the section that I cut out as a template to mark out the glass cloth.


Before laying up the glass, I stabilized the surface of the foam core by spreading a thin layer of thickened epoxy over it. When laying the glass, I used a roller to spread the epoxy around and into the glass cloth as I lay each piece down. It’s important that the glass is fully impregnated with the resin and no air bubbles are trapped underneath it.

I’d not glassed an area this big before, but I think it went well overall. I might have underestimated how much epoxy this heavy cloth could soak up though so I may have ended up with a laminate that is a little heavy on glass and light on the resin.

Before the epoxy cured, I covered the whole thing with peel ply. Peel ply is a cotton weave cloth that epoxy doesn’t bond with. Once the epoxy has cured, the peel ply can be ‘peeled’ off, taking any amine blush with it. This process leaves the surface underneath perfect for the next step – fairing.


Fairing is the process of smoothing out any unevenness in your fibreglass layup and getting the surface ready for painting. In this case, I spread epoxy thickened with 410 microlight over the entire work area then sanded it down with my home-made flexible sanding board.

The sanding board is just a 3mm strip of plywood that I glued a couple of handles onto one side and then a sheet of cork and some sandpaper onto the other side. It’s great when you need to sand a curved surface as it conforms to the curve.


My initial mix of the fairing compound was a bit thin and sagged away from the centre, so after sanding it back there were quite a few low spots which needed more compound.

I mixed up some ‘peanut butter’ consistency epoxy, spread it on, waited for it to cure, washed off the amine blush and waited for that to dry. And that’s where I am at the moment. Sanding is thirsty work however and I’ll have to leave the next session of sanding bliss to the next blog!


Coming Up Next Time: I’m hoping to wrap up the rudder next, I mean literally wrap it in glass fibre, so join me then!

If you have any questions for Seb regarding this post, please feel free to comment below.

The DIY Restoration of a Small Yacht: Rudder Surgery(#4)

seb-profile-photo-ytSeb, originally from Portsmouth in Hampshire, is the Sales Supervisor for the Gael Force Marine Megastore in Inverness.

He has agreed to write a series of posts following him and the restoration of his 26 foot, 54-year-old fibreglass yacht.

This series of blog posts so far can be read here.

Estimated reading time: 8 minutes.

BLOG POST #4: Rudder Surgery

I wanted to get the rudder and tiller home so that I could assess their condition and make any repairs from the relative comfort of my shed. As it was a transom hung rudder, removing it was simply a case of unbolting a few brackets and lifting it off its gudgeons.

Despite its substantial size, it wasn’t too heavy, and I was able to get it off and onto the roof rack single-handed.


The Tiller (the “easy” bit)

Despite being heavily weathered, the condition of the tiller ‘only’ warranted renovation rather than a complete replacement.

The first task was to remove all the bits of hardware. The previous owner had bolted various brackets and such onto it that I had no need for. I removed these, countersunk the holes and filled them with a generic teak coloured wood filler.

The old varnish was so flaky that sanding it off by hand was relatively painless, but the teak underneath was very weathered and I would have had to remove a lot of material to get back to fresh wood.


Rather than sand until I had a matchstick for a tiller, I decided to use a teak brightener to give the wood a more uniform appearance and remove the surface mottling caused by weathering. After brushing it on and washing it off, the look was much improved. She was now ready for some varnish!

I used International Schooner varnish, which is an easy to apply, one-part varnish with some UV filters in it, so it was perfect for exterior woodwork.

The first rub down was with 120 grit sandpaper to give the varnish something to key into. I then wiped it down with acetone to remove any remaining dirt and remove some of the oils in the wood which would allow for better penetration of the first coat of varnish.

I thinned the first coat with International’s Number 1 thinners at 20%. This allows the varnish to penetrate the grain of the wood which should prevent any chance of it peeling off in the future.

The technique I use for applying varnish is to brush it on lengthways with firm brush strokes to get the varnish on quickly, then go over it with brush strokes at 90 degrees to the first coating. Finally, I go back over it with very light strokes across the length of the work. In theory, this should get the varnish uniformly applied and remove any air bubbles that may have formed.

The trick is to work quickly so that the ‘wet edges’ of the vanish don’t tack up before you’ve done the whole thing. I’m no varnishing expert though, so if anyone has a better technique, I’m all ears!

The following day it was ready to rub down with 320 grit paper and apply its first coat of un-thinned varnish.




I learned the hard way that good lighting is important when varnishing. After completing what I thought was the final coat, it turned out that there were small areas that I’d missed.

I also think it pays to decant the varnish into a disposable container (paper cups in my case) rather than use it directly from the tin. There’s nothing worse than opening a tin of premium varnish to find a film has formed over the top of it from repeated exposure to the air!

I repeated the varnishing process six times until I was happy with the build-up. I thought the finish looked great!


The rudder: down the rabbit hole I go…

With the rudder safely back home, my first job was to remove all the paint so that I could properly assess its condition.

I wanted to use this ‘opportunity’ as a tester to see which method of paint removal I would use on the hull later on: sanding or wet shot blasting.

I liked the idea of wet shot blasting – using blast media in conjunction with a pressure washer – as I thought it would be the quickest method and give the best finish.

I was wrong…

I’d bought a cheap (£20) attachment for a pressure washer that has a tube going into a bucket of blast media. I used the finest grade of media I could find in the hope that it wouldn’t be too aggressive and damage the surface underneath the paint.


Despite using a petrol powered pressure washer that I had managed to borrow, it was slow going and I found that it would remove chunks of gelcoat before removing whatever primer had been painted onto it years ago.


After 30 minutes of work, the result was a mottled finish that still had some traces of antifouling and plenty of the underlying primer. I’d also managed to cover about 50% of my garden in black sandy stuff. The following pictures show some of the damage it was doing to the gelcoat:



It may have been that I was using the wrong media or that my technique wasn’t right, but the bottom line was that for a DIY’er, it was time-consuming, messy, relatively expensive (the blast media wasn’t cheap) and ultimately, an ineffectual process.

However, it was very good and quick at cleaning up the stainless-steel fittings still on the rudder and at getting into nooks and crannies that would be difficult to access with sandpaper.

After everything had dried out, I flipped the rudder over and retrieved my trusty sanders. I’m a strong believer in having good quality tools and I wouldn’t recommend approaching something like this without a sander that can at least be connected to some form of dust extraction.


The belt sander with a 60-grit paper made such light work of the job that I instantly realised that sanding was the way to go. With the dust extractor running, there was negligible dust, but I still wore a full face mask to make sure I wasn’t breathing that nasty antifouling.

Once the majority of the paint was removed, I used a powerful dual-action orbital sander and hand sanding to finish the job.



That being done, it was time to get down to business. I pulled out the two bolts securing the upper pintle and was dismayed (but not surprised) to find them covered in a yucky brown sludge.


I assumed this was rotten plywood that had been used as a core material for the thick upper part of the rudder, so I drilled out the holes with a 25mm hole saw in order to see how badly rotten the wood was.

I was amazed to find that there was no core material of any kind – just an empty void surrounded by 10mm laminate!


I don’t know if the rudder is the original or not, but either way, I found this construction pretty odd. It did mean that I wouldn’t have to cut out and replace loads of core material though, which was a relief!

My plan was to fill that section with some expanding foam, then cut a core out of the foam which would become a mould for pouring in thickened epoxy. It should end up stronger and more watertight than the original construction.

Onto the main body of the rudder.

It sounded hollow when I tapped on it in any section of the blade which I assumed meant that core material had become delaminated. There was nothing for it but to drill another inspection hole.

To my amazement, there didn’t appear to be any core material in there at all! Just a greasy lining on the inside of the laminate.


As far as I could tell I had three options:

1. Patch up the hole and leave it as it was.

  • As they say, “if it ain’t broke, don’t fit it”. I don’t like this argument as everything on a boat breaks eventually and the job of the owner is to take preventative measures to avoid things breaking when you really don’t want them to.
  • Besides, the boat’s been out of the water for two years but there was still evidence of water ingress in the rudder. If I left the rudder as it was it would quickly fill with water when submerged, giving it a huge mass which I would consider dangerous in a heavy sea.

2. Drill a series of holes in the rudder and squirt expanding foam into them to fill it.

  • I didn’t like this idea either as, due to that greasy lining, the foam wouldn’t adhere to the inside of the laminate and not having inspected the internals of the rudder I would assume that water would still get into it readily.
  • Also, expanding foam from a can is very low density and isn’t really suitable as a core material, any water that got in would wick into the foam and saturate it in no time.

3. Cut out a large section of one side of the rudder, clean everything out, make good the areas of potential water ingress, fill with high-density polyurethane foam and replace the cut section with glassed epoxy.

Option 3 is apparently how professionals would approach the repair.

I think you can probably tell which way I was leaning. Besides, a childish curiosity in me wanted to look inside the thing.

After long deliberations, I decided to take the plunge. I went about marking up a terrifyingly large section – big enough for me to reach all areas of the inside of the rudder blade but with enough lip to let me bevel a 60mm edge for bonding the new laminate.

Then, with oscillating multi-tool in hand, I ripped into the rudder of my boat.

Coming Up Next Time: Join me next time to see what horrors I uncovered and how I go about turning this thing back into a functioning rudder!

If you have any questions for Seb regarding this post, please feel free to comment below.

A quick look at the Gael Force Marine Megastore

Did you know that Gael Force has 3 stores across the UK (with sites in a further 3 locations)?

Our Marine Megastore in Inverness (South Kessock) is one of our biggest sites. Here we stock products from many areas of interests, including leisure marine, commercial fishing, and commercial marine.

We also have a large warehouse adjacent to the store, with 400,000 cubic feet of storage, and between the two, this Summer, we’re filled to the brim with stock and look forward to helping you find what you need!

In addition to Inverness, we have our Marine Centre in Glasgow (Hillington Industrial Estate) which stocks a smaller range of commercial marine and leisure marine products while our Plymouth Marine Centre (Sutton Harbour) focuses largely on products for commercial fishing.

Watch this short snapshot of our Inverness Marine Megastore and pop in to see what’s in store for yourself. Take the chance to get up close and personal with our range of kayaks, dinghies, creel, engines, boat maintenance products, clothing and more!

Inverness Megastore Opening Times:

Mon-Fri: 8am – 5.30pm

Sat: 9am – 5pm.

Sun: Closed.

Glasgow & Plymouth Opening Times:

Mon-Fri: 8.30am – 5pm.

Sat & Sun: Closed.

Get our addresses and contact numbers through our Store Locator.

The DIY Restoration of a Small Yacht: Un-stepping the mast- Short-handed (#3)

seb-profile-photo-ytSeb, originally from Portsmouth in Hampshire, is the Sales Supervisor for the Gael Force Marine Megastore in Inverness.

He has agreed to write a series of posts following him and the restoration of his 26 foot, 54-year-old fibreglass yacht.

This series of blog posts so far can be read here.

Estimated reading time: 5 minutes.

BLOG POST #3: Un-stepping the mast- short-handed

The next priority for this boat is to get it transported closer to home. It’s currently an hour’s drive away from where I live which makes the restoration progress slow going.

I was initially considering sailing her to a club/yard close to Inverness but given that she’s going to be out of the water for at least a year, I decided it would be better to get her transported across land directly to my house.

The idea of being able to spend my evenings grinding out fibreglass and tinkering around in the bilges seems strangely appealing.

However, she can’t be transported anywhere with her mast up, so un-stepping her mast was the next logical step and the subject of this blog.

The boat’s mast is deck-stepped, so thankfully it doesn’t have to be lifted 3-4 feet to get it clear of the deck. Still, having the use of a crane to lift and remove it would be the easiest, safest and most sensible way to get the mast off.

Despite this, I had different ideas. And being someone that, when possible, likes to get things done myself, I opted for a method of mast removal that in theory can be done single-handed – the A-frame!

1.boat-diagramThe idea behind this system is that you keep constant tension on a line (the genoa halyard in my case) that goes from the mast top to the apex of the A-frame. You then have another line (we’ll call it ‘the lowering line’) going from the apex of the frame through a block at the bow and back to the cockpit.

Once the forestay and the lower shrouds have been removed, the only thing preventing the mast from dropping backwards is the lowering line. This can then be eased off and in theory, the mast will gradually fall back as the A-frame rises up in a controlled and stress-free manner.

The key is that the A-frame remains at 90 degrees to the mast at all times, maintaining your angle of pull on the mast.

The lower legs of the frame must be positioned amidships in line with the base of the mast and the apex going all the way to the bow. I built it from some cheap stud timber that I had lying around in the shed.

The length required was longer than the 2.4m lengths that I had so I bolted two bits together to make it the right length. The two pieces were joined at the apex with a door hinge (again, lying around in the shed) and an eyebolt put through to fix the lines to.

I drilled some holes through the bottom of the legs so that I could tie them off to prevent them from slipping when under load. I also used a jigsaw to round off the edges of the feet so that there wasn’t a sharp point digging into the deck as the frame rose up.


The mast should really be on a tabernacle when using this system, but that’s not the case with the Invicta, so I had to improvise. I needed something to keep the base of the mast in position but also allow it to tilt down whilst it was being lowered.

My rough and ready solution can be seen in the picture below. I bolted a small piece of plywood to the deck through a hole left over from one of the deck plugs and fixed an eye plate to it. I then used a long dee shackle to join the eye plate to the foot of the mast.


This shoddy arrangement was definitely the area of the system where I had the least confidence. I was worried that if the mast twisted or drifted over to the side too much, the forces exerted on that eye plate could cause some damage to the deck.

Well, nothing ventured nothing gained, I guess.

To catch the mast as it came down, I built another frame from some flimsy treated frame timber. As it turns out it was only just not too flimsy!


On the day of the un-stepping, I was grateful to have two helpers in the form of my wife and father-in-law. Their jobs were to steady the lateral movement of the mast by taking the topping lift well astern of the boat. I had to extend it by tying on a length of Marlowbraid rope that I had kicking about.


When we were all in position, I began removing the lower shrouds, slackening off the backstay, and then with some difficulty, I removed the forestay (it has a Rotostay roller reefing on it).

For journalistic reasons, part of me wants to record some kind of drama or unforeseen problems that arose, but the truth of the matter is that everything went exactly according to plan.

My wife kept a small amount of tension on the topping lift and as I eased off the lowering line, the mast slowly but surely began its descent into the cross-tree.


Admittedly, it was pretty nerve-wracking at times. Especially at the point where the mast was nearly down and began swaying from side to side as my wife desperately tried to guide it into the cross-tree.

All in all, it was a success and the following day I returned to remove all the rigging and get the mast off the boat.


You can see in the picture below that the boat is now beginning to look more stripped down and is getting closer to the blank canvas that I’m working towards.


Until next time!

COMING UP NEXT TIME: There’s not too much that I can do now until I get the boat moved to my house and put under cover, so the next blog will most likely be a wee recap of my progress on stripping it down.

If you have any questions for Seb regarding this post, please feel free to comment below.