As the stern needed the most reshaping, decided to tackle it first. Made up a wooden insert to reflect the correct deck stern contour and glued it in between the deck supports. This would give the stern be the correct shape and length. Once that was positioned pulled the hull up tight to the supports. As the stern is approached the sharper profile of the Teakwood requires the hull sides to be pulled firmly inwards and the transom be vertical. Decided this was not going to epoxy and stay in place satisfactorily once the strain was released, so cut a series of vertical slots in the rear hull to allow it relax and squeeze it together. One slot has to be quite deep, otherwise the lower hull will crack as it will not relax sufficiently. Used the Dremel cutting disc for this. The slots need to be quite generous as the the hull has to be pulled in some distance. Once this was all epoxied in place, wrapped “cling film” around the rear of the hull and poured liquid fibreglass resin around the slots and under the insert to bond everything together. Worked this onto all the vertical and horizontal surfaces as it set. The stern is now good and rigid. The attached pictures show the new stern profile and slots. The first pictures are “as is” to illustrate the process. Further work was also needed to true up the bulwarks and disguise the slots. This mutilation may seem a brutal way of getting the hull shape correct, but had tried all kinds of pulling and squeezing of the hull, none of which held in place after the clamps were released. Once the cosmetic aspects of the stern rework were complete, established the correct location for the rudder post and fitted it. The major stern work is now finished.
[Score: 9/10] 60"/7600g Schooner - Comments: Scratch built with mahogany planks on the club's mould. Glass cloth and fibreglass inside and protected with G4 polyurethane resin all over. Uses a sail winch (Hitec) and travelling dolly for the two main sails and a separate arm servo for the foresails. Standard servo for the rudder. Power is from a 6.6v 1000mA LiFe battery. Taranis Tx using two sticks with the sail servos connected via an internal mixer to one stick. Ballast is fixed to the keel with two studs which extend into the hull where a steel bar is attached between both and acts as a carrying handle.
Hi Bellman My Club sail several similar boats as well as an Ibex. They are all fitted with detachable keels which are fitted prior to sailing but can be removed for transportation and display. Our sailing waters are large and exposed and without the keels the models would not be able to be sailed. On the water the keels can not be seen. I tried a long keel on my Cariad and it was not a success as the keel tended to keep the model in a straight line. I now use a detachable bulb keel. The amount of lead will depend on your model and its overall weight. The bulb keels are a fibreglass moulding that we fill with lead to bring the model to waterline after inserting fore and aft threaded rod into the bulb. You will need to have holes in the keel to let the rods thro and long enough to be above the waterline. I fit a plastic tube and wood support inside. A washer and nut hold the keel in place. Before filling with Resin weigh the resin in the tin and remove that amount of lead from the bulb. Once set I use silicon to make a good seal between the bulb and hull and which remains attached to the bulb. Attached are pics of my Cariad.
Hi bellman, (from Doug BELL😉) This is another 'How long is a piece of string question'! Only way to find out is to build it, and do a payload test. Put weight in it until it floats to the waterline and upright and stable. I use chunks of lead and lead balls (fishing weights). Weigh the lead. Easiest way is to weigh the empty hull first, then again with 'payload'. Difference is your payload weight for the hull, including all equipment, decks, superstructure etc. Before you glue any other parts to the hull weigh them and subtract from the payload test weight as you go. When compete you should then know how much weight you have left available for equipment. Weigh the equipment; motors, shafts, electronics, batteries etc. Anything 'left over' is the ballast you need. Try to fit it inside as low as possible, the lead balls are good for final trimming. When all is correct simply pour a little resin over them to hold them in place. Only time I fitted ballast outside, a long steel bar keel, was on my U26 sub. But then U Boats had such an emergency 'drop keel' so it looked 'Right'! Happy building, Doug 😎
Good weekend of progress has seen the hull glass clothing completed and has now had 2 coats of resin. Will get a 3rd and final coat after last stabilzer is fitted before final sanding, priming and painting (once motors and propshafts have been fitted). Have also made good progress on the cabin superstructure which has now started to get this "Solent" closer to the eventual finish line! Not much more can be done this week as starting Nights tonight, sometime good to have a break though!
Hi Dave, agree with the talc idea, sometimes I file a piece of busted terracotta flower pot to powder and mix that with the resin. But usually to repair Gisela's busted garden ornaments not for boat models, but no reason why not😉 But then that's why I suggested the thicker two part glue not the liquid resin for this 'fix'. Re hardeners: as far as I know all are peroxide based but the concentration is different for the various 'speed' glues. Frankly I would have thought that the faster mix on the inside would have accelerated the outer mix, at least at the interface between the two! BTW: It was never suggested to use the epoxy as filler! The resin was just to soak and harden the balsa wedges and hold everything in place. I'm sure I wrote to the effect; when fully cured THEN use filler on the outside of the hull for the cosmetics. Something lost in interpretation?? Anyway step by step Neil is reaching his goal! 👍 @ Neil; you'll need to get a shift on with the 5 min mix! 5 mins is the hard setting time, working time before it goes too stiff to move is only about 2mins!!!🤔 Cheers Doug 😎
Hi neil If the resin was runny I suspect you omitted or did not mix the hardener sufficiently or the two mixes interacted with the quicker inside mix setting quicker and stopping the longer mix from setting. If you make a correct mix and cover the soft resin as suggested it should all set nicely. You could add some talc to the runny resin to thicken it up before adding the new mix. Just a thought but possibly there are different hardeners for the slow and fast cure resins. I do know different brands don't always work together. You are nearly there and will be soon ready to move onto the next stage. Dave
After a week away in Lanzarote, have had a couple of days to get some work done. Left side of hull is now fully sheeted, gaps filled and awaiting final sanding and glass clothing. Decided to get ahead of myself and have fitted all the deck pieces and the cabin deck formers. The inside of the hull has had a second coat of epoxy resin and will get a couple of coats of yaht varnish once the final pieces of internal wood parts have been fitted to include battery tray, motor mounts, prop shafts, servo rail, ESC tray, receiver tray, speaker/engine sound module tray. Up at the bow have fitted the wood for the on/off switch, sanded, sealed and primed the bow deck before adding a couple of the detail parts.
Hi Dave, Yep. I'm also sure they must have something similar. Re: Common FT Market; surely that only affects tax and duty? Mark is right about the commercial companies. Some firms seem to use fairly small, obscure ones with low volume! Some the most expensive - like UPS🤔 Also; many carriers appear to make surcharges on 'dangerous items' like paints, resins and such. Many refuse to carry them, e.g Royal mail, esp. across borders! That's why I had to find a German distributor of the Schneider / WEM ColourCoats paints. Snapped up the last 5 tins of MTB Green in Germany apparently 😉 cheers Doug 😎
Hi neil Mixture and temp are all important. You could try gentle heat from a hairdryer to harden the resin. Adding extra hardener to the mix is not advisable as it can lead to unpredictable results. Epoxy is not ideal as a filler but you can make it more suitable by adding microballoons to the mix. This will result in a very hard finish which you can sand to shape. Personally I use car body filler when fixing in prop shafts / rudder tubes etc as this can be easily faired into the hull contour and will easily take paint. I have successfully used this over epoxy joints. Whatever you use you need to make sure the work environment is not too cold. The temperatures have dropped considerably over the last few weeks so you may need to provide a warm environment to assist the curing process. Dave
Hi Chris I have used Iso Propyl Alcohol as a solvent for many years and also to clean electrical boards and contacts. You need the industrial strength 99.9% as the rubbing alcohol only has 70% IPA. It will thin most resins and evaporate leaving little residue, so will have little effect on what you are intending. It's freely available as HMCR are not concerned that it will be used in place of Alcohol, which carries duty. We as individuals cannot easily buy denatured alcohol in the UK and meths contains other additives which are unwanted for your purpose. Cheers Dave
I have to agree with teejay. Heat will certainly not be good and may result in fire if excessive. Casting usually have a gel coat (any colour) applied to the mould followed by the mat/cloth and resin. Once hardened it form a rigid and strong structure. Model hulls have frames and spacers attached to the open top to maintain the correct shape. If the mould has been stored for some time without this support it can become deformed at the open edges and gently heat can be used to help reform to the correct shape. I suspect this is where you heard about the heating. I would not heat much above hand heat and make sure you spread the heat all over the area to avoid local hot spots. If you are allowed a warm bath may be a suitable container. If you make a wooden frame to the correct size this can be used to gently spread the mould to the correct shape. I suggest you then place the hull upside down on a flat building board and hold square until dry. Cheers dave
having used glass fibre most of my working life , I have never used heat too shape or alter the shape of any glass fibre item. how ever I have used the resin to make long shaped items (without the glass fibre ) and use boiling water to shape them to form on another shape ,such some of the decoration on post boxes ( patterns for casting)
Sometimes I hate work it gets in the way but I've managed to get the first fix for the prop tube at last now to leave for a while as work and courses in the way again. I have also managed to open the hole for rudder guide and presume this needs a bit of expoxy resin to secure it in place? The oiler is also fitted and a bit of cleaning of the inner hull to remove some of the old paint ready for sanding sealer coat after I've mounted and aligned the motor - not looking forward to that at all if past experience is anything to go by. But now the old mount is out there is more space and the prop and shaft is at a much better angle thanks to Dave and Doug😁😁