Hints and tips - bending plywood.
Methyl Methacrylate glue.
This type was recommended by a waterjet manufacturer for glueing it into a model boat. It is a two-part glue, and its advantage is that it will glue almost anything, including joining two metals instead of welding.
It has a couple of disadvantages. One is that it stinks, it really has to be used outdoors. Another is that it seems to be impossible to find in stores and has to be purchased via Ebay or otherwise on the internet.
Clothes pins are inexpensive and plentiful and also make good additional clamps for holding large surfaces in position for gluing when you may not have as many clamping devices as you would like.
Member's tip from Harry: Do you need to make a template of the shape of a hull? Maybe you need the external shape to cut out a support for display, or the internal shape to add a frame to stiffen the hull? Press a length of solder wire onto the hull in the location required. Carefully transfer it to a piece of cardboard and tape it down in a couple of spots to ensure it doesn’t move. Trace it using a pencil, remembering which edge was pressed onto the hull. and cut out.
Bilge keels are the strips that stick out from the turn of the bilge on most vessels, and are provided to reduce rolling. Here are some suggestions for fitting bilge keels to a scale model.
1. If you have enough material in the hull wall, cut a slot with a Dremel tool and glue the strips into the slot.
2. Use a length of styrene angle. Glue one edge flat onto the hull, towards the centre underneath. The glued face will not normally be noticeable, but if preferred it can be cut back at the end at a slight angle to make it less so. The angle is flexible enough to follow the curve of most hulls.
3. Put nails into the hull along the line where the bilge keel will go. (Model railway track pins are good for this, with the head cut off.) Use epoxy glue to fasten the keel material to the pins and to the hull.
From Rowen: The more ships I build the more I appreciate that absolute accuracy is worth the extra effort. I use steel rules, protractors dividers and laser pointers to ensure models are accurate and symmetrical. Not only do they look better but finishing does not require any odd shapes to adjust for inaccurate construction.
Member's tip from Rowen: Bending strips. Using 1/2" (or similar) plastic plumbing tubing, capped at one end, make a reservoir into which ammonia can be poured. Slide the wood strip into the tube and allow it to soak. Then remove and bend to shape whilst it is still saturated.
On drying out it should retain the bend.
Have also thought the plastic tube, containing the strip, could be bent into shape and then drained. The strip would then dry out retaining the bend.
Deluxe Materials Exe-Kote
As quoted by the manufacturer: Eze-Kote is a 1-part water based foam-safe, low odour, resin alternative to epoxy. Brush onto balsa and light glass cloth to create a tough, ding and fuel resistant film that can be sanded easily and painted after 20-30 mins.
This product has the advantage that, because it's a one part product, any of it unused after an application can be poured back into the bottle for later use. Its disadvantage is that, because it's water-based, shipping during freezing weather may affect it.
It is stocked in Canada by Great Hobbies.
Lepage All-plastics super glue.
As quoted by the manufacturer:
Confederation Marine Modellers
From Roy: I have so far fibre-glassed the hulls of 4 models, and despite the verbal and written advice I've received, none of them has turned out as well as expected. All have required lots of sanding and redoing, simply to get them to the state that they were acceptable. More recently I came across this video on Youtube by a modeller named Greg Hahn: https://www.youtube.com/watch?v=ujk-wBQDUSk.So I tried his technique recently and have been really happy with the result. There is lots of advice on the web not to dilute epoxy but, so far, I've not noticed any adverse consequences.
You've probably seen the tip about reversing clothes pins to turn them into clamps. How about the one that says you cut a notch in the end and use them to hold planks onto the frames until the glue dries?
This is one many "gems" in a series of videos that Dale found on the internet. They are all produced by a modeller by the name of Gary Brinker and can be found on Youtube:
Pictures and text by Paul.
From Roy: Polyethylene is a plastic that consumer-grade glues won't stick to. it's used to make container lids, such as for Pringles, and margarine tubs. The lids are good for mixing epoxy, or for placing a small quantity of CA glue.
It also used in flexible sheet form for plastic bags, Ziploc bags are a good example. So it's a good material to use as a barrier in locations where you don't want glue to get to.
I have also used it to repair a damaged wall, such as on a bulwark. I have mixed epoxy and applied it to the damaged area, then on each side placed a piece of Ziploc bag and a piece of styrene (anything flat will do), and clamped the area to squeeze the epoxy down to the thickness required. Once set, the clamp and Ziploc can be removed, and the epoxy trimmed to size and shape.
Rowen writes: I have often tried to heat relieve strains in plywood, once glued and clamped in place, by gentle heating with a heat gun. I have never been sure just how well it works, but as no parts have sprung apart I have assumed it is fine. I am building a pilot boat model that has a pronounced rounded bow to support a substantial rubber buffer. I was wondering how to do this as I was reluctant to try the usual wood block sanded to shape approach.
I decided to cut a length of thin plywood (1/16") to the same depth as the inwale and held this in a steel tube bender and applied gentle heat. Lo and behold the ply gradually relaxed and took up the shape of the bender.
When cooled the wood was released and most of the shape is retained. It was then cut to length and glued to the frames and bow support, where it fits nicely.
As a follow-up to Paul's review of adhesives at the last meeting, here are a few more. They are not as commonly used by most of us, but in some situations they have advantages.
Member's tip from Steve M: If you have to secure something inside the hull of your boat, say a battery box, use silicone instead of epoxy. The silicone will hold it firmly, but it will be possible to remove it if adjustments are needed.
As quoted by the manufacturer:PC-11® thrives in wet environments. It is resistant to water whether it is fresh or salt. Ample open time allows tooling or positioning in order to tackle larger and challenging jobs. When mixed, the epoxy, part A (white) and the hardener part B (lt. blue) react to form a bond of tremendous strength and flexibility. The PC-11® formulation is slow curing, but slow can be a good thing especially for large tasks.
PC-11® is a thick paste. Thick is good if you need to work vertically or want to hold an object in place. How thick? Not quite as thick as peanut butter. Its advantage for modellers is that it won't run like liquid types. Its disadvantage is that it will stick to your mixing stick or applicator, and tends to leave spikes of glue (same as you get with Goop). The best way to get a smooth glue surface is to press polyethylene plastic (the stuff Ziploc bags are made from), over the glued joint. After it has set the plastic can be pulled off cleanly.
PC-11 is available from Home Hardware.
From Paul: I like to have a VERY smooth finish on the hulls I sail. While this is mostly so I can stay ahead of Harry in the races I also like the look and feel of a very shiny hull.
All it takes is patience and a little elbow grease. Once you have a reasonably smooth hull (whether it is wood, plastic or Fiberglas) the next step is to start wet sanding. If you go to one of the Wood Shows you can get a complete range of wet sandpapers at a very good price. Each sheet will go a long way since it can be washed and dried and reused many times. I start with 400 grit and work up through 600, 800, 1000, 1500, 2000 and 2500 - yes there is 2500! In fact you can get 60,000 but it is about as rough as Charmin'. Dip the sandpaper in water with a tiny drop of dish-washing liquid, it will make the job easier. Sand in the same direction and just take a couple of minutes for each grade of paper. Once you have finished then apply several coats of a good wax such as Maguires auto wax. This process can be done directly on styrene or ABS hulls or after painting. If you are going to sand after painting then make sure you have several coats of well dried paint and be prepared to paint again if you sand right through it. It's worth the effort!
Member's tip from Paul: Working with cyanoacrylate (CA) is at least difficult and at worst dangerous. Using less is almost always better and I do that by never dispensing the glue directly. Whenever possible I squeeze a couple of drops onto a plastic surface (think lid from a yogurt container) and use a straight pin to apply the glue to the item being glued. This works especially well with locking knots in small lines
From Paul: I made the terrible mistake of telling my wife that I would take over the house cleaning when I retired. It's been ten years now and, yes, I do all the cleaning.
When it comes to cleaning my displayed boats (there are eight or so on display in the house) I use a very soft paintbrush to loosen dust while I hold the tube of the vacuum about six inches away. This will take the disturbed dust away while leaving the important bits where they are.
Tips and tricks - UHU glue.
Rowen writes: It was suggested to me some while ago that using this adhesive simplified laying deck planks.
The glue is squeezed and spread over the area to be decked. The planking is then laid onto the glue and moved into place. Excess glue is squeezed out between the planks. This should be left to dry. Once dried it can be rubbed off easily with your fingertip. In practice I found this is not quite as easy as suggested, but it does work.
The section of fore deck on my current project, an RAF Rescue and Target Towing Launch(RTTL), shows the finished result (not surface treated yet). The lengthwise joints are all the gaps between the strips. The strip ends are being inked in. The rubbing strip around the deck is mahogany and the planks basswood strips.
It's unlikely that you'll find UHU glue in local stores but it can be found on Amazon and ebay, of course. The glue sticks are not the same as the liquid glue in tubes.