After 3 fails its time to ask where i go wrong..

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After 3 fails its time to ask where i go wrong..

After 3 fails its time to ask where i go wrong..

Author	Message
Hanaldo	Hanaldo posted 3 Years Ago HOT Post Details
Group: Forum Members Posts: 2.5K, Visits: 28K	Yeh make no mistake, that is a tricky part to infuse without bridging. Pre-preg would be a lot easier, though infusion won't be impossible. You will just need to really concentrate on getting rid of any bridging before you pull the trigger on the infusion. Spend a couple of hours just working the bagging stack into those recesses under partial vacuum. I would work from the middle out, pull full vacuum, let the vacuum off again, work your way from one side to the other, pull full vacuum, let it off again, work your way from the opposite side back again, pull full vacuum, etc. You will learn what pressing on a section of bridged material feels like, it is somewhat spongey compared to the rock solid feeling of pressing against the mould surface. If that doesn't work, you may need to start putting relief cuts in on those recesses. I feel the actual reinforcement is thin enough that you should be able to get it to work. Possibly rotating the backing layers to +/-45° will help. Same with the peel ply, lay that up at 45° and don't be afraid to put relief cuts in or let it overlap itself. Your infusion mesh will probably be the biggest issue, so I would either use a knitted flow mesh (total PITA to remove afterwards) or place relief cuts so that it can move around easier. Your infusion speed may also be an issue with regards to trapping air in those areas of bridging, 10mm feed line is MASSIVE for a layup this size. To put in perspective, I use 6mm feed line for any infusion up to 3.5sqm. So when you're getting up to the size of a full size boat hull, thats when you need ~1/2" feed line and connectors or multiple connectors.
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Warren (Staff)	Warren (Staff) posted 3 Years Ago HOT Post Details
Group: Administrators Posts: 2.5K, Visits: 7.9K	Sometimes you can even throttle the feed line on a 6mm hose to slow things down. Certainly in your case it can't hurt. Bridging can be a right pain. You can use spray tacks but very sparingly otherwise they make a mess of the surface finish. You have to take care with every layer to avoid bridging as well as with the bagging stack. You can chop up the peel ply and mesh with an overlap where necessary to make it easier to avoid bridging. Warren Penalver Easy Composites / Carbon Mods - Technical Support Assistant
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jeffrey bres	j jeffrey bres posted 3 Years Ago HOT Post Details
j Group: Forum Members Posts: 42, Visits: 469	+x Warren (Staff) - 4/14/2021 2:17:36 PM Sometimes you can even throttle the feed line on a 6mm hose to slow things down. Certainly in your case it can't hurt. Bridging can be a right pain. You can use spray tacks but very sparingly otherwise they make a mess of the surface finish. You have to take care with every layer to avoid bridging as well as with the bagging stack. You can chop up the peel ply and mesh with an overlap where necessary to make it easier to avoid bridging. I allready chop the peel and mesh to avoid bridging. But yes. The white mesh that came with the kit is quite nasty in sharp corners. I did a slooow infusion with 6mm and il see what comes out. Prepreg is awsome. But then i do need an autoclave. And thats something i cant afford. So. Hand layup and infusion will be my choices. Hand layup is most used in these boats and does work fine. But infusion would be awsome when i master the tecnique.
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Hanaldo	Hanaldo posted 3 Years Ago HOT Post Details
Group: Forum Members Posts: 2.5K, Visits: 28K	Don't need an autoclave for out-of-autoclave pre-preg; you need a freezer to store it in, and an oven to cure it in. Oven can be as simple or fancy as you like, mine is made from MDF and fibre cement board and cost me less than $500 including the PID controller. Has been serving me solidly for the last 7 years.
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jeffrey bres	j jeffrey bres posted 3 Years Ago HOT Post Details
j Group: Forum Members Posts: 42, Visits: 469	+x Hanaldo - 4/15/2021 2:36:27 AM Don't need an autoclave for out-of-autoclave pre-preg; you need a freezer to store it in, and an oven to cure it in. Oven can be as simple or fancy as you like, mine is made from MDF and fibre cement board and cost me less than $500 including the PID controller. Has been serving me solidly for the last 7 years. Is that allso availible in glass. Or only carbon? I need a glass carbon hybrid layup. Full carbon isnt good for these things. And cevlar ive had allso. But will start to wrinkle inside the carbon. Then glass carbon. Is the best in this application. ( in my experiance.)
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jeffrey bres	j jeffrey bres posted 3 Years Ago HOT Post Details
j Group: Forum Members Posts: 42, Visits: 469	+x jeffrey bres - 4/15/2021 9:07:13 PM +x Hanaldo - 4/15/2021 2:36:27 AM Don't need an autoclave for out-of-autoclave pre-preg; you need a freezer to store it in, and an oven to cure it in. Oven can be as simple or fancy as you like, mine is made from MDF and fibre cement board and cost me less than $500 including the PID controller. Has been serving me solidly for the last 7 years. Is that allso availible in glass. Or only carbon? I need a glass carbon hybrid layup. Full carbon isnt good for these things. And cevlar ive had allso. But will start to wrinkle inside the carbon. Then glass carbon. Is the best in this application. ( in my experiance.) Only now i notice... out of autoclave could be interesting. Could you tell.more.? A freezer is eazy to come by..
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Hanaldo	Hanaldo posted 3 Years Ago HOT Post Details
Group: Forum Members Posts: 2.5K, Visits: 28K	Glass and carbon are really a mismatch, the strength of fibreglass comes from its higher elongation to break and the strength of carbon comes from its high rigidity. If you combine the two, then the fibreglass carries all the load as the carbon will break first, which means you aren't taking advantage of the material properties of either fibre. But yes, you can get pre-preg glass. Likely not going to be something you can get in small quantities though. Easy Composites have virtually all the information you need in their X-Preg processing guide and YouTube tutorials. If you're new to OOA prepregs I would start there, it will really flatten the learning curve.
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Warren (Staff)	Warren (Staff) posted 3 Years Ago HOT Post Details
Group: Administrators Posts: 2.5K, Visits: 7.9K	Indeed for a semi-structural part you would unlikely want a mix of the two materials for the reasons Hanaldo stated above. We have plenty of customers using DIY ovens and as long as you take electrical and thermal safety seriously, you should be able to make something that works and is not a fire hazard! Out of autoclave pre-pregs have made the pre-preg process a lot more accessible in recent years and removed a fair bit of the mystery surrounding the process. You can find our range of pre-preg videos covering various methods and our XPREG pre-preg system here: Composites Learning Area Warren Penalver Easy Composites / Carbon Mods - Technical Support Assistant
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Chris Rogers	C Chris Rogers posted 3 Years Ago HOT Post Details
C Group: Forum Members Posts: 120, Visits: 933	Prepreg is great but it takes WAY longer to lay up and debulk and will require more of you tooling. It's probably easier than infusion as a process though. But the material is way more trouble to get and store so it only makes sense if you need it for a good reason! It should be doable with infusion though! Bridging is a layup issue that you should be able to avoid. A shape like that should go in in several pre-patterned pieces for sure. You might look into stabilized dry surface plies like EC's Profinish. You can cut it to patterns like prepreg. I'm a nerd about this but I really think that slip joints in outside corners are very helpful - especially in the outermost ply of something like your hull. It is usually better to cut and lap a ply than to risk a bridged corner!
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jeffrey bres	j jeffrey bres posted 3 Years Ago HOT Post Details
j Group: Forum Members Posts: 42, Visits: 469	+x Warren (Staff) - 4/16/2021 3:42:19 PM Indeed for a semi-structural part you would unlikely want a mix of the two materials for the reasons Hanaldo stated above. We have plenty of customers using DIY ovens and as long as you take electrical and thermal safety seriously, you should be able to make something that works and is not a fire hazard! Out of autoclave pre-pregs have made the pre-preg process a lot more accessible in recent years and removed a fair bit of the mystery surrounding the process. You can find our range of pre-preg videos covering various methods and our XPREG pre-preg system here: Composites Learning Area Well. I am racing rc boats over 25 years. Of witch 20 years with carbon glass and carbon cevlar etc. The best mix i know is glass with carbon in this sport. The glass its elongation is what we need. The carbon is only used to make it more stiff. Full carbon is hard like a rock 100% but when we get hit by another boat. Full carbon will break allso with a good flip(they can fly off) It are serious machines! We hit speeds of over 80mph. Im not saying we have the full benefit of all. But we take the strength from glass. And stiffnes of the carbon. Anyhow. If you know a better layup Im happy to try and test it! For this boat it needs to be light allso. I use 210 carbon 200 glass 290 glass and some coremat on the deck together with some carbon roving For the boat im trying to infuse. It went horrible again. I did a 2.5h test on the vacuum. Made a hudge batch of resin.(el2 this time.. becouse i ran out of in2.) I made a carbon plate of 4mm on a glass plate with peel on both sides... perfect bubble free. And 100% rock solid.(took me 45min to infuse with 6mm lead) The boat hull. No go. It was all white and hazy in the bag. I was even able to delaminate all layers of fabric without tearing them. I dont know what is wrong. But i didnt loose pressure in 2.5H. and did 100% the same as the carbon plate On foto it doesnt look that bad maybe. But there where 3 layers of glass inside. And now its only carbon. Gets me thinking. What if i put those parts back and vacume infuse again over them with new glass inside. Lol Will it or will it not work. now i have a nice carbon plate and 2 carbon shells.. Im getting a little nervous, lol. Why are my vac and feed lines good. Bubble free. No leaks in 2.5 houre. Needle didnt move at all... open up the vac line and no single movement. Bag was super tight. And after infusing i have a full out problem The only thing i can think of now. Is i made these 2 boat halfs with wax over easylease. And the carbon i didnt use wax. Although. This dek i allso made with easy lease and wax. (No grlcoat) and clearcoated it. that came out like a dream. Allso el2 resin. Vacuum allso same rolls of carbon and glass used. Same mixing cups and stirring sticks and all. Could it be my bag has some weak spots. And will start leaking on them over night? Or what am i doing so wrong? I made 2 good ones(well. Decent ones.. useble.. and now all ..... ones.. Edited 3 Years Ago by jeffrey bres
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