Alessandro did your look up tell you it's how Lloyd’s of London. uses “A1” rating for ships that are seaworthy, and of very sound construction Col

@ColRay
Thanks a lot, Col—that’s very kind of you. I didn't actually understand "A1"—I had to look it up, hahaha—we don't use that term.

Alessandro Quality workmanship A1 10/10 Col

@ChrisF
Sorry Chris, I deleted this message because I posted it twice—I don't know how that happened. Lately, I've also been having trouble uploading photos; it adds duplicates and doesn't include the ones I select.

@ChrisF
Hi Chris, yours is probably the most suitable solution.
Up until now, I’ve worked on protruding keels (not sharp-angled ones like those on speedboats), which allowed me to slide them into perfectly straight guides.
I created a straight channel to slot the keel into; by fitting snugly inside, it stayed straight.
With a sharp-angled hull, I can't do that, so I was considering a solution like yours. Thanks a lot for the photo; I hope I can find it again when I need it.
I had also considered using structures (parallel to the keels) to check and realign the frames, but your method is definitely the best—not least because adding more wood just increases the weight.
Kudos on your precise, clean, and organized working method.

@roycv
Hi Roy, your solution is certainly efficient. You found an optimal approach for the hatch closures. It works perfectly for your model—and for most models, too.
While I wouldn't recommend using 8mm thick material to others nowadays, I would do it again for my ship model, given the specific characteristics of its construction.
The interlocking step design allowed me to achieve an excellent watertight seal—especially when using screws (which aren't mandatory but are highly recommended) and applying a light layer of grease between the mating surfaces.
As I mentioned, the model is designed to keep out every single drop of water, even in extreme conditions—such as heeling over until the water rises well above the gunwale and floods the entire deck.

@ColRay
Hi Col.
If I could have made the cannons out of a heavy material, I would have preferred brass—a beautiful alloy that is highly resistant to oxidation over time.
As with other parts of the build, lacking a milling machine and a lathe meant I would have needed to find a friend with access to one, and that’s becoming increasingly difficult.

I’m not ashamed to admit that, for some parts, I buy ready-made items from model supply companies (especially if the quality is high), but this time, no one stocked the specific type of cannons I needed. The ones on the market were all from eras either earlier or later than the one I had chosen.

I was forced to opt for a lightweight plastic material. I created the design myself, though the 3D printer didn't belong to me.
The gun carriages, on the other hand, were made using a mix of wood and plastic via traditional methods—though still based on my own designs.
With a good paint job, I think I managed to mask the disparity in material quality (various plastics versus wood and metal).
I’m attaching a few photos so you can take a look.
In any case, I’ve decided that the next sailing ship I build won’t be a warship—so no more making cannons for me! Hahahaha.

The method you mentioned is one that has always intrigued me. I’d love to see photos of the process if you have them; I find the procedure fascinating.
I remember when my father used to let my son do some lead casting. I was a bit anxious—worried about him handling molten metal—but it was truly amazing to watch.
The real skill lies in creating the mold—kudos to you, Col.

Twist Free Flat Plywood.

@ChrisF I have helped to solve/cure the problem of any plywood sheeting that is delivered with a warp in it.

I have fitted to my workshop(shed) walls a couple of rows of those adjustable steel shelving brackets.

These are spaced closely together (not very far apart from each other) and when I fitted them, I put some string that was pulled tight between the outer two brackets before screwing the middle rows of supports to the wall to make sure they were all aligned perfectly with each other.

This was also checked with a long metal spirit level that was also used to check that each bracket in any row was absolutely “flat” and aligned with the other brackets.

Each set of brackets has a least one layer of 25mm thick plywood laid on it to become the shelf, and on top of these shelves is where I lay all of my plywood sheets to store them.

Any wood that is not perfectly flat when it is delivered is placed at the bottom of the pile underneath all the other wood.

In time ( and sometimes with some rotation of the wood layers) they all become nice and flat and twist free too, so when I want to use them I know that they will be flat and twist free.

It is a very simple solution, but it works !

Bob.

Chris a long story so the short version, a couple of years ago the sailing club got fed-up with a couple of the local fishermen and wrecked fishing boat dumped near the club, so one day the club a nice bonfire , but before the fire was lit, I salvaged a panel or two and once the timber was cleaned up made a couple of pinhole cameras, if I can find the images I will post them Col

Bob ' pension related problems' the way I look at it is raise your head high... shout out feck and get on with life Col

Chris a very neat work set-up Col

@AlessandroSPQR Yes, warped plywood can certainly be a problem. Only time I got some that was completely flat was when I bought some from SLEC when they were at a local model boat show and I was able to select it myself - sadly due to Covid the show is no more.

The stuff I buy online can vary in the amount of warp and unfortunately I don't have the space to lay it flat. A small amount of warp on smaller components isn't too much of a problem and with larger ones I choose the best places on the sheet. Slight warping isn't a problem for me in that with my larger models I add temporary "fingers" to the keel (and a temporary backbone in this example) so that it can be screwed to a nice straight timber bearer. Once the doublers, frames and stringers have been glued in place the keel stays straight and the fingers can be cut off to allow for the hull sheeting to be applied.

@EdW I use mainly birch ply (don't know if it's aircraft quality though) in my builds and on the thinner stuff I used for decking the surface was so good that on one of my early builds (before I attempted planking) I just varnished it and it came up lovely. The thicker ply doesn't seem to have such a nice finish and even the thin doesn't have such a nice finish anymore, still good, but not good enough for applying varnish directly.

@ColRay Sorry to hear about your pension related problems, too many that I have heard have had bad advice and lost out due to it.

If you are thinking about laser cutting plywood, it may be worth finding out what sort of plywood can be cut that way.

I only mention this because some methods of cutting plywood may not work with resin bonded ply and need water bonded laminates to work (ie water just cutting for example).

……just a thought……..

Bob.

@ColRay You may get some that way but I'm guessing it will only be the thicker stuff, always worth asking though.

Roy I may ask the lads 'n lassies at the sailing club Col

Thanks Bob at the moment it's in the ( maybe) planning stage as I pointed out in one of my previous postings, because of a couple of medical problems I may end up changing the way I make models.
Two ways that are on the agender 3D printing and laser cutting.
Now the possible spanner in the works being on a small state and overseas pension (because of bad advice I lost must of my retirement find) no point in crying over it, just got on with life.
But I will be checking out SLEC and the post Col

@ColRay It could be worth putting a reasonably good sized “online” order of wood together with SLEC and then checking the postage cost when it comes to the check-out.

If the delivery is too expensive then the order can be cancelled at that stage before you are committed to paying for it.

I have just posted a LesRo Sportsman boat to Harry in Tasmania for him to restore as we have both been looking for one for years, so when two came along in quick succession, I bought them both and shared one with Harry.

The postage costs from the UK to Tasmania were not as intimidating as I originally thought they would be (prior to sending Harry a boat previously).

I also posted an MTB model to Australia some years ago when I gave up my Coastal Command boats to focus on the Classic Model Power Boats that I now enjoy building and restoring (but mainly driving them!), and the cost of sending that was far less than I had feared it would be.

…….so, if you are unable to buy the wood types that you would like to use locally, it may be possible to buy them from SLEC and have them delivered to you?

Bob.

@ColRay Hi just a thought but there is lots of sailing, dinghies as well as the big ones so there maybe wooden boat repair specialists and try ordering a whole 8 x 4 sheet. I did this some years ago with a 6mm 8 x 4 sheet and it was cut in half into 4 x 4 and I shared it with a friend.
best of luck.
Roy

My personal favourite is Aircraft Quality Birch Ply, not cheap but gives excellent results. Years ago a friend of my fathers was a director of a wood company that specialised in plywoods. They did an experimental run of 1.5 and 3 mm ply with one side in mahogany, they decided that there was not a big enough market in South Africa and he gave my father about 10 4ft x 8 ft sheets, that kept you going for years.

@AlessandroSPQR Using thick decks. 8mm seems rather excessive, my decks are no more the 3mm or less. If I need to have hatches with no coamings, I put extra planking 15 mm wide to whatever the thickness needed, underneath the before cutting the spaces needed. Allow to dry to retain any curvature of the deck.
I have converted a couple of decorative models with sealed hulls and first made wood jigs to copy curve of the deck. Then drilled 0.7mm pilot holes at the corners and then cut with a knife or razor saw the deck. I then attach the jig underneath the cut out deck to retain the curve. If the deck part has to be a hatch then veneer thick wood can be glued to the edge to fill in the saw cut wood. After that proceed as necessary.

You can see the hatch line on the starboard side extending from the foremast almost to the stern, it has caught the shadow and not usually that obvious. I needed complete access to assess the internal construction as a decorative model does not always have continuous glue lines and I needed to varnish the insides as well, so that when testing for leaks the water does not soak into the wood! Yes, they always leak.
Roy

Bob how I wish I could buy some locally Col

Alessandro re cannons the last time I made a set I made one in timber the made a silicon mold and resin cast a batch of them Col

@ChrisF
Hi Chris, I used Tanganyika walnut (which is much lighter than native walnut) for the deck planking, and I was very pleased with the visual result.

Speaking of plywood, you’ve reminded me of a problem I’ve always found difficult to solve.
Whenever I buy a sheet, it’s always slightly warped (curved).
This isn't a major issue for the decks and upper structures, but it certainly is for the keel.

We are lucky in the UK that we can get hold of good quality ply and timber and in plenty of sizes, thicknesses and types. I like Bob, buy most of my timber and ply from SLEC and it is unusual to get any that is below standard so think it was a bad batch that Bob got. I bought some after him for future builds and it all looked good, including the timber strips I bought. They also supply different grades of balsa.

Another good supplier is Cornwall Model Boats, I mainly buy the hardware side of things from them but have bought the planking for decking etc. from them which is very good. They have some different timbers, one of which I hadn't heard of, which is Tanganyka. This is a light coloured timber and goes a lovely honey colour when yacht varnish is applied and contrasts nicely with mahogany.

Other good sources of timber are dolls house companies but unfortunately only in shorter lengths.

With what I'd already got and that new order I think I'm stocked up for my future projects!

@ColRay Single layer 1.5mm for skinning hulls, decking and cabin tops on Classic Model Power Boats Col.

Bob

@ColRay
Hi Col, you are absolutely right.
Weight is crucial in sailing models. It must be managed precisely to ensure lateral stability and a righting moment for the ship.
Weight high up should be avoided. I kept everything to a minimum and used lightweight materials as I built upwards; for instance, I would have liked to make the cannons out of brass, but I had to 3D-print them in plastic for precisely these reasons.
The 8mm-thick deck is positioned relatively high up, but it is quite light, and in any case, it wasn't something I could do without.

Alessandro I guess a little weight is a good thing for puff 'n sail boats Col

@ColRay
Hi Col. No, I wouldn't recommend an 8 mm thickness.
For many boats, 8 mm is certainly excessive and unnecessary, but my choice was driven by specific requirements: I needed to create hatches without any raised superstructure—everything had to be flush with the deck—so I needed thick enough structures to form a recessed lip for the hatch to sit on, as shown in the example photos.
I won't be using this approach for the new design because I have a very large raised superstructure available; this will serve as a single, wide hatch providing access to the mechanical and electronic components.

Alessandro eight mm that's nice and thick Col

Ronald At the moment I'm in a quandary with my model making. 3D plastic or timber that is the question Col

Hi Sailor Paulowlia is like a hard Balsa long straight grain and a bugger cutting across the grain Col

Hi All. An interesting conversation on woods. I use Balsa and Ply, usually around 1.5mm. If you are in the UK I would recommend taking a look at the Balsa Cabin. These people know their woods and even spent some time selecting a harder Balsa for me.
https://www.balsacabin.co.uk/

Hi Bob 1.5 is that used as a single or double skin
birch ply that's not in the WA shops , all I can buy is Plantation Paulowlia
Col

@ColRay Hi Col,

I use 1.5mm birch ply skins to make my hull and deck skins from, as well as for the cabin tops and deck skins etc.

Depending on the size of the model I use 3mm or 4mm birch ply for the bulkhead formers and 6mm birch ply for the keel and keel doublers.

My current models are between 16” long (Patrol Launch) and 39” long (Rapier) and this thickness of wood works well on all of them.

I often buy my plywood and skins from SLEC who deliver promptly enough although the delivery cost can be quite high for small orders .

The quality of the wood cannot be seen when buying by mail order, and the last batch of 4mm birch ply that I bought for use on my Sprite Plus chipped as I was cutting it and needed some P38 filler to correct the surface finish afterwards.

Also, some of the plywood skins looked good on one side - but had a knot on the other side and so I could not use it for hull skins as intended.

On a small models the knots in a ply skin can be avoided as the pattern can be placed so as not to include the knot, but on a larger model this may not be possible and so the skin has to be rejected and replaced.

Bob.

@chugalone100

I agree though price, availability, and tools required to cut and form it is also part of the solution.

Plywood requires specific saw blades, whether it be scroll-saw, bandsaw or table-saw, if using a power tool to prevent tear out. Even then, tear our is still possible.

Plywood also might require trim to be attached on exposed edge seams.

@ColRay
Hi Colin, I agree with what Julian said.

I used two layers of 4mm plywood—making a total of 8mm—because I needed to create a recess for the hatch system (specifically, the covers that open to access the electronics and mechanics in the hold).
I didn't use marine-grade plywood, though it would have been an excellent choice for my needs.
Because I used standard plywood, I had to put a lot of time and effort into waterproofing the deck. However, this was a critical priority for me; when sailing on a beam reach, there is a real risk of water submerging part of the deck—rather than just getting a few splashes—something I’ve experienced with previous models.
So, Julian is right: if that risk isn't present, marine-grade plywood might be unnecessary.
That said, considering what you mentioned about plywood availability, I would opt for good-quality 5mm plywood, even if it isn't marine-grade.
Even if there aren't any specific operational issues, I still recommend protecting the wood with resin or varnish.

Thanks Julian
The problem is the only ply I can find in the local shops is 5. that is of a good quality not marine but nice timber.
or the craft shop rubbish. 2 or 3 mm very thin covering on what looks like cardboard . Col

@ColRay
Hi Col,
From my experience building kit boats, the 3-ply used for decks and superstructures is usually 1.5 mm (about 1/16”) or 2 mm, depending on the scale and the particular kit.

I wouldn’t say it needs to be full marine-grade plywood.
What’s more important is that it is good-quality, lightweight, straight, and has a nice even veneer with no voids between the layers.
Marine ply is excellent, of course, but for a model boat it can be overkill and sometimes harder to work with.

For visible deck and superstructure work, I’d look for aircraft/model plywood or good-quality birch 3-ply.
The important thing is that it stays flat and doesn’t delaminate when you are cutting, sanding, or gluing it.

Hope that helps, Col. 👍

Julian

Also scratch builders for sure would have the answer Col