McG 6969 Posted July 19, 2016 Author Share Posted July 19, 2016 Hello Nick & welcome to the 'commenting watchers', Your post wasn't really on the grocery theme as it is part of my 'modeling learning curve'. I won't ask you if it was tin or silver soldered as I'm afraid that I would start the build of a model steam engine... By the way - talking of steam - it was 36°C this afternoon here in Zaventem... If it's the same tomorrow, I might try to bake a "sunny side up" on a black steel plate... Hakuna matata Chris BRU - BE / CTR Temp Control Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted July 19, 2016 Share Posted July 19, 2016 I can answer that. They were never silver soldered. No need and one wanted the solder to flow into the seams Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted July 20, 2016 Author Share Posted July 20, 2016 NO no, Peter, you won't get me at starting to build a model steam engine... I really have enough at hands with the Bella, although I must admit that the current temps here are slowing my 'productivity' down for quite a bit. The temperature yesterday inside La Grotte was up to 29°C, not bad for a 'cavern'... Maybe I can manage some painting and put it to dry in the 'oven' outside. Hakuna matata Chris BRU - BE / CTR Steam Engine Control Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted July 21, 2016 Author Share Posted July 21, 2016 Bonjour, Goede dag - or even more Flemish, 'Goeiendag', Guten Tag, As it is the Belgian Independence Day today, I just thought to greet the readers in our three official national languages… It also means that this is a ‘holly-day’ of course, so further occupation in La Grotte is restricted by good household manners and due to the splendid weather, this becomes a very welcomed intermezzo for this rookie… Nevertheless, I’m still pondering about that cowl weight ‘mystery’… Hakuna matata & Happy Landings to all Chris BRU - BE / CTR July 21st Control Edited By McG 6969 on 21/07/2016 08:12:25 Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted July 22, 2016 Author Share Posted July 22, 2016 Hello again to all, As I wrote, I was still pondering regarding that “cowl weight mystery”. Now, I had never worked with glass fiber under 80gr/m² so, a while ago, I asked some advice here concerning the grammage to use for my cowling. Chris Barlow nicely explained his method being 2 layers of 18gr + some GF tissue reinforcement at the front openings and at the back end (cfr p.51 of this blog). His cowl came then nicely out at around 40gr. My 18gr cloth being of poor quality, I decided to have a first layer with it but followed by a second of 30gr. When cured it came out at 14gr with that bit of a penalty due to the second layer. So, I couldn’t imagine that ChrisA’s ‘reinforcement bandages’ did cost him a full 26gr, even with some heavier tissue. A bit of a ‘mystery’ here… After some research, I found out that there was a simple misunderstanding. As ChrisA explains on his Ballerina blog (page 9) he didn’t use some 18gr for his lost foam cowl but the heavier HK’s 48gr… and, of course, that explains why his cowl comes out at 41gr after reinforcement. Very probably just a typo with his advice but I’m lucky that I didn’t use two layers of 18gr or I would have ended with a useless piece of glass fiber 'lace'… and Bella’s cowl is still very, very fragile at this stage, but now at least I know why... Hakuna matata Chris BRU - BE / CTR Mystery Control Quote Link to comment Share on other sites More sharing options...
Chris Barlow Posted July 22, 2016 Share Posted July 22, 2016 I'll take a photo of my Ballerina cowl this weekend to show how soft and flexible it is where it's not reinforced with tissue.What did ypu use for the resin ? I use epoxy which makes it quite flexible. I find polyester resin with glass cloth comes out a little too rigid and brittle. Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted July 22, 2016 Author Share Posted July 22, 2016 Thank you for visiting and commenting, Chris. I have absolutely no doubts about the flexibility of your cowl without the reinforcements, but can you imagine the ‘flexibility’ of mine with just half the cloth weight of yours. Yours being 2x48gr versus mine 1x18 & 1x30gr… But it was ‘complete’ with no holes or weaker spots, just too ‘thin’ overall. It will be ‘nearly perfect’ & very light after a bit of reinforcement at strategic spots. To answer your question, I used Vosschemie Azur Laminating resin. It’s a medium-reactive, pre-accelerated, thixotropic ortho-resin to be mixed with 2-3% Mekp hardener and obtainable in ‘small’ 1kg packaging. I used it a lot for lightweight & smaller pieces for full size aircraft as its composition gives it a very good flexibility, but of course with thicker 80gr fiber cloth. Anyway, next time I’ll use a ‘gelcoat’ as first layer as it is a lot easier to handle. I used to always get a gelcoat layer first, but didn’t want to spend some cash at more products this time. Regarding epoxy resins for glass cloth, I only tested HK’s ’20 minutes Finishing Cure’ and wasn’t really convinced as too ‘flexible’ for moulding purposes, but probably acceptable for wing glassing though. What kind of epoxy did you use, Chris? I’ll get back with a full report on the item when the reinforcements will be done… Hakuna matata Chris BRU - BE / CTR Azur Resin Control Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted July 23, 2016 Author Share Posted July 23, 2016 Hello everybody, Time to go on with the reinforcements for the cowl as it is really too thin as is… The advantage of a negative mould is that you can slide the glass fiber item back in assuring its original form again. The curved areas are quite OK around the nose, but I started with the spinner area where those air bubbles had been trapped with just one roundel of 50gr. Then went on with 1 layer at the bottom as this is a complete flat part & followed with 2 layers of 50gr (20 & 25mm wide respectively) around the back end circumference of the cowl where the mounting holes will be. In an earlier life, my full size composite ‘teachers’ told me that the best & lightest way to create strength is to work in 3D instead of applying too much flat layers of clothes and resin. They used some lightweight stuff like electrical PVC tubing for straight lines or pieces of foam for more compound or complicated shapes to create a support over which they applied a layer of cloth creating a kind of ‘tunnelling’ or ‘bridge’. Great efficiency for a very small weight increase. I guess you can best compare it with the strength of the D-box concept for a wing. So, for my sidewalls I used that idea with a small lamination of 3mm Depron + 0,8mm ply to strengthen the area where the side exhausts will be attached/screwed. By the way, if you want to preserve your preferred Fiskars scissors when working with glass fiber, I learned that it is best to use a simple rotary cutter to obtain very nice edges… Sjeesh McG, what a ‘serious’ writing here… … humm - right, well yes - even Gaston told me that The LotH wouldn’t probably even be smiling with this kind of ‘boring technical’ stuff… sorry then, gents... Hakuna matata Chris BRU - BE / CTR Smile Control Quote Link to comment Share on other sites More sharing options...
Craig Thomas Posted July 24, 2016 Share Posted July 24, 2016 Hi Chris. I've just had a catch up on your build. It's coming along great guns. 😀 I've not been online for the past month or so as after having our son born 6 weeks ago free time is something of a distant memory. I love the cowl, it looks great. I see gaston has been giving you a helping hand also. I've managed many successful flights with my ballerina now, I must say its a very forgiving model, I've build mine quite heady I think, it feels quite heady in the hand, but it truly is a great model to fly. Your hard work and effort will be well worth it in the end. 👍 Keep up the good work, I'll try and pop in from time to time when Grayson (our son) allows it. That's if I haven't took the spare 5 mins to sleep. That's a novelty at the moment. 😂😂 Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted July 24, 2016 Author Share Posted July 24, 2016 Hello Craig, Your visit and comment are highly appreciated. I really wasn’t aware of that time lapse but I can imagine that a new family member must be quite a change in your daily ‘routine’. It’s fine as well to read that your Ballerina is still doing well. As for the Bella, I try to keep my motivation up to level although I still have the tailplanes and wing to ‘handle’… So, keep visiting once in a while & in the meantime, please give Grayson and his mother our - The LotH & me -best regards. Thank you for visiting and for the cowl & other compliments. Hakuna matata Chris BRU - BE / CTR ‘Birth’ Control (!?) Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted July 25, 2016 Author Share Posted July 25, 2016 Hello to the BCSW***, In an attempt to give an acceptable finish to the turboprop exhausts, I painted the ‘interior’ of the tubes in flat black followed by a layer of flat stainless steel - called ‘Inoxydable’ here in BE - from a spray can to cover the exterior. When dry, I applied a light wash of gunmetal acrylic diluted in some denatured alcohol. I also made a ‘test-case’ with a piece of Depron covered with some ali film. Even if not totally convincing as a cowl, I thought it was a very quick approach to that Peter/Maikis ‘visual reflexology’ concept… In case of any interest, here is a pic of the materials I used. Hakuna matata & by the way >*** = Bella's Community of Silent Watchers... Chris BRU - BE CTR Turboprop Control Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted July 25, 2016 Share Posted July 25, 2016 Looks good. I expect you know that the outlets will have a discoloured look, a sort of browny hint though this varies from engine to engine. IT sort of fades so not solid colour. Quote Link to comment Share on other sites More sharing options...
AndyD Posted July 25, 2016 Share Posted July 25, 2016 looking real good,i even thought it was ali not depron,i think its goin to be a winner. Quote Link to comment Share on other sites More sharing options...
Rosco Posted July 25, 2016 Share Posted July 25, 2016 Looks good Chris. I must admit, I'm impressed by your ability (and patience) to do things like that. I really don't have the time to spend making things like you have so therefore if I'm trying to achieve something in particular, I tend to be a bit lazy and find something that is already similar. eg. If I was doing an exhaust like you, I'd either make it out of balsa (less time consuming) or find something that had a plastic spout or similar, and use that! Keep up your good work Rosco Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted July 26, 2016 Author Share Posted July 26, 2016 Thank you for your kind comments, guys. Regarding the exhausts weathering, Peter. It seems that all turboprop exhausts are made of stainless steel and not of regular steel or 'vintage' cast iron. So, the real appearance isn't the same at all, not that 'rusty'. It also looks quite different in daylight, but as I have a spare one, I'll try some 'brownish' wash/weathering as well, time allowing. That thin aluminium vinyl is indeed very 'spectacular', Andy. I bought it as Plan B for my battery hatch and maybe trying to cover my cowl as well. But I don't really see the latter coming out OK with all those curves... I'm certainly not that "patient", Rosco... But I have a simple trick for that: I just 'switch' to another part of the build when getting too nervous about a particular task. ... and, "a bit lazy", you wrote? Why do you think the Bella's build is taking that long... ? Thanks again Hakuna matata Chris BRU - BE / CTR Laziness Control Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted July 26, 2016 Share Posted July 26, 2016 I did not say anyhting about RUST. Even stainlass seel with go a faintly browny yellow with enough heat. Look at jet fighter tailpipes. Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted July 26, 2016 Author Share Posted July 26, 2016 Oops, then... sorry Peter, some kind of 'language abyss' here, I presume. On the other end, we really don't have any full size fighter jets around here in Zaventem and the airliners are still too 'high' to have a proper look... Can you imagine, when I was a kid the airport was our favourite 'playground'. They even had some guided tours with some mini-trains - converted luggage lorries - on the tarmac & in the hangars... 'Times are a changin', Bob used to sing...>> The good news is that I already followed your advice & had a 'browny' test on the spare exhaust... and both the Bella's exhausts are now also already 'converted' since the end of this afternoon... Hakuna matata Chris>> BRU - BE / CTR Browny Control>> Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted July 26, 2016 Share Posted July 26, 2016 Yes, I remember in 1954 happily cycling onto and round Stanstead airport with no one stopping us or asking what we were doing. Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted July 27, 2016 Author Share Posted July 27, 2016 Well yep, Peter... and our telephones also still had some wires too during the 'second half of last century'... At least we can still use those old wires for modeling purposes. I already used some for my cockpit detailing and I think I will use some more for navigation lights wiring in a following build. Anyway, as someone said: "Nostalgia isn't what it used to be anymore... " Hakuna matata Chris BRU - BE / CTR Wiring Control Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted July 27, 2016 Author Share Posted July 27, 2016 Hi to all, With the cowl reinforcements cured, I could finally have the mouth and spinner ‘cut outs’ done and present the cowl to the fuselage to measure for the final adjustments at the back end, for the mounting holes and for the positioning of both the lateral exhausts. Slow progression certainly, but progression at least… Hakuna matata Chris BRU - BE / CTR Measures Control Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted July 27, 2016 Share Posted July 27, 2016 Looking very impresive Quote Link to comment Share on other sites More sharing options...
AndyD Posted July 27, 2016 Share Posted July 27, 2016 looking real good keep up the good work and put us to shame(well me anyway). Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted July 28, 2016 Author Share Posted July 28, 2016 Thank you both, gents. The only one to be put to shame for working that slow is just me, Andy. But on the other end, the bits I'm working on at the moment require precise measurements to fit together nicely. And no 'second chance' allowed if I miss-drill anything in the Bella's thin cowl... Very nice work with the glassing of your Mustang, by the way. Hakuna matata Chris BRU - BE / CTR Drilling Control Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted July 28, 2016 Author Share Posted July 28, 2016 Hi guys out there, As per Simon Burch’s advice a while ago when I had iron covered my hatch, I finally decided to keep the ‘Bright Silver’ but to ‘brush’ it down with a few rubbing passes of Scotch Brite. On a test piece, I scored a few panel lines with an empty ball pen and also tried a few ‘punches’, in an attempt to represent some ‘totally non scale’ flush rivets. I also had a ‘wash’ with gunmetal acrylic & isopropyl to give some ‘depth’ to the panel lines & rivets together with a tiny bit of weathering. Well, testing is fine of course, but sometimes one has to go for it, so here is the result when applied to the hatch. I also used a plastic ‘pallet strap’ (is this the correct word?) as a ruler as it folds nicely around the curves where needed. With a few lengths of light tack masking tape applied, some flat black was sprayed at the top to protect the eyes of driver Pierre against that invasive Belgian sun… “Well, now suddenly, Bella’s hatch starts to nearly look like some of the P-51’s deco schemes”, Gaston said… humm… Hakuna matata Chris BRU - BE / CTR Warbird Control Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted July 28, 2016 Share Posted July 28, 2016 Very nice Chris, I like it John Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.