Peterpools Posted February 3, 2023 Share Posted February 3, 2023 OH NO This morning I sanded and re-did any areas that needed help that I saw in the photographs from the other day. What I though was a scratch, wasn’t but a CRACK! All I can figure out is the two fuselage halves are slid over the wings and the fit was tight. I must have used a bit too much senior force way back at the beginning and now a crack has appeared. I just blew up the area of the crack so you can see it begins at the trailing edge. I’m not sure if it still spreading but I do here a cracking noise sometimes when holding the modeling. I have no idea how to fix the crack so it will no longer keep spreading. My other thought is on a model this old, the plastic could also have become very brittle as it aged. Who knows why or what. My only concern is how to stop the crack from spreading and then I’ll need to fill, sand and repaint again. Any ideas would be greatly appreciated. Thank You Extreme blow up of the crack 2 2 Link to comment Share on other sites More sharing options...
Martinnfb Posted February 3, 2023 Share Posted February 3, 2023 I was just dealing with similar problem on my C-47 build. I melt the hell out it with Tamiya Extra thin glue by using capillary action, basically weld it together. 2 Link to comment Share on other sites More sharing options...
Peterpools Posted February 3, 2023 Author Share Posted February 3, 2023 Thanks Martin. Do I first need to drill a hole right at the point on the fuselage and the trailing edge to relieve the stress point? Why is it, nothing these days is ever easy. 2 1 Link to comment Share on other sites More sharing options...
JohnB Posted February 3, 2023 Share Posted February 3, 2023 I'd carefully clean up the area around the crack using some Alclad Airbrush Cleaner on a Q-tip. Then lay in enough Zap Gel CA to cover the crack then put a drop of Zip Kicker on it. That way you can sand it out without having to wait for the gel to set up. You should then have a strong "fix" to work with. Works for me! 6 Link to comment Share on other sites More sharing options...
Martinnfb Posted February 3, 2023 Share Posted February 3, 2023 The melting power of the glue will extend the crack just a little, no drilling required. The beauty of this method is in its ability follow the crack to places that are not yet visible. It will leave a groove to fill once dry. 2 1 Link to comment Share on other sites More sharing options...
Peterpools Posted February 3, 2023 Author Share Posted February 3, 2023 Thanks John Misery loves company. Do I drill a dtrill hole at the start of the crack to prevent this from happening again? 2 Link to comment Share on other sites More sharing options...
Peterpools Posted February 3, 2023 Author Share Posted February 3, 2023 Thanks Martin 2 Link to comment Share on other sites More sharing options...
JohnB Posted February 3, 2023 Share Posted February 3, 2023 6 minutes ago, Peterpools said: Thanks John Misery loves company. Do I drill a dtrill hole at the start of the crack to prevent this from happening again? I wouldn't think so Peter as the CA should prevent that. You can if you want to but I really don't see the need unless you just want the extra hold. 4 Link to comment Share on other sites More sharing options...
HubertB Posted February 3, 2023 Share Posted February 3, 2023 15 minutes ago, Peterpools said: Thanks John Misery loves company. Do I drill a dtrill hole at the start of the crack to prevent this from happening again? Yes. You need to stop the crack spreading further, especially after repairs. I’d drill a hole big enough at its end, plug it with a piece of rod, soak the whole with extra thin. If the sides of the crack are in contact, re-welding with extra thin will work. If they are disjointed, then it’s better to plug the crack with CA gel. CA is good for any assembly exerting tensile forces, and bad for anyone where you have shearing forces. Hubert PS edit: sorry to contradict John, who replied while I was typing mine. I still think that, if the crack started at the wing root, you need to make sure it will not spread further by drilling a stress-relieving hole at its other end. 4 Link to comment Share on other sites More sharing options...
Martinnfb Posted February 3, 2023 Share Posted February 3, 2023 It's been a while, since I built this kit and if I am not mistaken, the wing itself is in one piece and slides in to the fuselage halfs, I remember the joints required a bit of a clean up to loosen the fit. That extra tension could cause the crack. 3 Link to comment Share on other sites More sharing options...
JohnB Posted February 3, 2023 Share Posted February 3, 2023 The more I think about it Peter the more I think drilling a small hole might be a good thing. Just to be sure. 3 Link to comment Share on other sites More sharing options...
DocRob Posted February 3, 2023 Share Posted February 3, 2023 Bummer Peter, I think as well, drilling a hole would be a good idea. I normally use my vise for drilling and drill by hand for more control, but in this case, would use a Dremel and VERY low pressure to not add stress to the brittle material. Take care, not drilling too deep and cause havoc in the interior. Cheers Rob 2 Link to comment Share on other sites More sharing options...
Peterpools Posted February 3, 2023 Author Share Posted February 3, 2023 Thanks Guys for all the advice. I pooled all the suggestions and started the repair: 1. I very carefully sanded the crack out, back down to the bare plastic. 2. I drilled out holes at the beginning and end of the crack. 3. Then I filled in the stop holes with thin CCA and let dry. 4. I carefully went over the crack numerous times with Extra Thin and it's now drying. 5. After dinner I'll sand out the repair and see how it goes. 6. I had already masked out the area for some redo air brush work before seeing the crack and left the masks on. I'm hoping none of the glues worked their way up under the tape but I can deal with that if need be. Tomorrow, I'll sand, polish and re-prime the repair and then follow up with Tamiya LP-70. Fingers crossed 🤞 Thanks again for all the help and suggestions. Good friends to the rescue for sure🎯 5 Link to comment Share on other sites More sharing options...
JohnB Posted February 3, 2023 Share Posted February 3, 2023 Good luck! 🤞 2 Link to comment Share on other sites More sharing options...
Peterpools Posted February 3, 2023 Author Share Posted February 3, 2023 Thanks John - somehow when it seems clear sailing ahead, something always upsets the applecart. 1 Link to comment Share on other sites More sharing options...
Peterpools Posted February 4, 2023 Author Share Posted February 4, 2023 UPDATE: BAD TO WORSE Checked the repair and it didn't go well at all. After four or five hours last night, I checked the Kingfisher and the crack had spread way past the repair (nearly tripled in length) and also started working its way forward, under the trailing edge of the wing 🙁. I had no idea what to do but needed to take drastic steps. 1. I removed all the Tamiya White Putty from the underside of flap to relieve any pressure that I could from the brittle plastic. 2. I drilled a new stop hole at the rear end of the flap in the fuselage and will not fill it, hoping it acts to remove the actual stress I had to created when pushing (forcing) the wings into place - what I should have done, is widen the opening in the fuselage for the wing to pass through; same on me. 3. I drilled a new stop hole at the end of the crack line and am not going to fill it, since filling it with CA, alleviates the purpose of the stop hole - of course, I'm just guessing. 4. I completely sanded off all the paint over and around both cracks, filed the crack lines/areas smooth, using liberal amounts of Extra Thin to melts the plastic together in the cracks and now am letting everything dry for a good 24 - 48 hours (that's where I am now). Fingers crossed and hopefully this will work as I'm running out of ideas and options. 3 Link to comment Share on other sites More sharing options...
JohnB Posted February 4, 2023 Share Posted February 4, 2023 48 minutes ago, Peterpools said: UPDATE: BAD TO WORSE Checked the repair and it didn't go well at all. After four or five hours last night, I checked the Kingfisher and the crack had spread way past the repair (nearly tripled in length) and also started working its way forward, under the trailing edge of the wing 🙁. I had no idea what to do but needed to take drastic steps. 1. I removed all the Tamiya White Putty from the underside of flap to relieve any pressure that I could from the brittle plastic. 2. I drilled a new stop hole at the rear end of the flap in the fuselage and will not fill it, hoping it acts to remove the actual stress I had to created when pushing (forcing) the wings into place - what I should have done, is widen the opening in the fuselage for the wing to pass through; same on me. 3. I drilled a new stop hole at the end of the crack line and am not going to fill it, since filling it with CA, alleviates the purpose of the stop hole - of course, I'm just guessing. 4. I completely sanded off all the paint over and around both cracks, filed the crack lines/areas smooth, using liberal amounts of Extra Thin to melts the plastic together in the cracks and now am letting everything dry for a good 24 - 48 hours (that's where I am now). Fingers crossed and hopefully this will work as I'm running out of ideas and options. I feel for you Peter. It has to be very aggravating. Hang in there as I'm confident you will overcome the problem. I still think some thick CA gel applied to the length of the crack would be a big help. 3 Link to comment Share on other sites More sharing options...
Peterpools Posted February 4, 2023 Author Share Posted February 4, 2023 John That's my next step. I'm guessing that pushing the wing trough the wing opening in the fuselage, it just didn't fit right and it's what is causing the stress cracks, but I have no way to open up the wing slot more then I did late last night. See how it goes. 3 Link to comment Share on other sites More sharing options...
Spitfire Posted February 4, 2023 Share Posted February 4, 2023 This is not nice at all, for gaps my technique is similar to John's I normally use scrap plastic pushed into the gap and then liberal quantities of CA, followed by accelerator and sand smooth before the CA goes too hard. Good Luck Dennis . 3 Link to comment Share on other sites More sharing options...
JohnB Posted February 4, 2023 Share Posted February 4, 2023 1 hour ago, Spitfire said: This is not nice at all, for gaps my technique is similar to John's I normally use scrap plastic pushed into the gap and then liberal quantities of CA, followed by accelerator and sand smooth before the CA goes too hard. Good Luck Dennis . That a good approach as long as the inserted piece doesn't push the break wider. Thick CA gel and NOT any thin stuff is the main thing. 2 Link to comment Share on other sites More sharing options...
GazzaS Posted February 4, 2023 Share Posted February 4, 2023 Weakening the plastic with extra thin will just exacerbate the problem. You have to relieve the pressure or build up the area strong enough to resist the pressure. 1 Link to comment Share on other sites More sharing options...
Peterpools Posted February 4, 2023 Author Share Posted February 4, 2023 Dennis and John There really isn't any gap just a crack that keeps spreading. I've glued the crack thoroughly twice now and after the glue has dried, the crack has continued to spread. I've also drilled stop holes at the beginning and the end of the crack. I'm hoping my last 'fix' works as I've been trying to determine where the actual point of where the stress is. If it's inside the fuselage, I have no way of cutting into it. I'm hoping the area I cut last night works. See how it goes. 2 Link to comment Share on other sites More sharing options...
JohnB Posted February 4, 2023 Share Posted February 4, 2023 1 hour ago, Peterpools said: Dennis and John There really isn't any gap just a crack that keeps spreading. I've glued the crack thoroughly twice now and after the glue has dried, the crack has continued to spread. I've also drilled stop holes at the beginning and the end of the crack. I'm hoping my last 'fix' works as I've been trying to determine where the actual point of where the stress is. If it's inside the fuselage, I have no way of cutting into it. I'm hoping the area I cut last night works. See how it goes. Good luck Peter!!!! 🤞 2 Link to comment Share on other sites More sharing options...
Peterpools Posted February 4, 2023 Author Share Posted February 4, 2023 Thanks John Tomorrow will tell the whole story🤞 2 Link to comment Share on other sites More sharing options...
CANicoll Posted February 4, 2023 Share Posted February 4, 2023 I'm completely at a loss. Everyone has presented pretty reasonable suggestions and solutions, so not sure why the crack keeps spreading. Was there any problem joining the fuselage that might be putting stress on the plastic? Otherwise, I'm clueless as to what to suggest. UGH! Feel for you though! Second thought - maybe its 'battle damage'? Or training damage? Reaching for straws here. 2 Link to comment Share on other sites More sharing options...
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