This is just one way - and not the standard one. Usually honeycombs are used with pre-pregs. This method does work pretty well though for lightly loaded panels - and is way less trouble and way cheaper. Glad you found the video useful!
@@ExploreComposites Enjoy your videos but would be good if you had a consistent testing process when finished even if fairly simple like one I saw you did with a deflection test, the break test showing how a narrow sample fails. Maybe an impact test. I’m trying to work out what materials to make a lightweight, stiff hardtop for a car. But won’t be dangerous in a roll over like an only carbon one would be. But also something not too crazy on the cost. I’m angling towards a lunate of 210g kevlar with a 6mm thermhex core and another 210g kevlar on the inside with some addition bracing added afterwards of just some simple ribs of something lightweight with a couple of layers of the 210g Kevlar. Using epoxy resin. It will be wet lay up with a light vacuum to consolidate it all. Any pointers would be great
Love your videos. Is the porosity caused by the vacuum drawing through the individual cells?? Seems like it would draw the resin up into the cells. I’m clearly missing something but I’m extremely curious as to what. Thanks.
The porosity is mostly because the resin was very thick and I didn't use enough and didn't roll it out with a bubble-popper. Slightly more resin would make a big difference in to porosity! The resin will wick up the cell walls and make nice bonding "fillets" but it won't make it up to the top skin or bleed off. This is a strange way to make a panel and was kind of an experiment but it has its drawbacks.
Enjoy your videos but would be good if you had a consistent testing process when finished even if fairly simple like one I saw you did with a deflection test, the break test showing how a narrow sample fails. Maybe an impact test. I’m trying to work out what materials to make a lightweight, stiff hardtop for a car. But won’t be dangerous in a roll over like an only carbon one would be. But also something not too crazy on the cost. I’m angling towards a lunate of 210g kevlar with a 6mm thermhex core and another 210g kevlar on the inside with some addition bracing added afterwards of just some simple ribs of something lightweight with a couple of layers of the 210g Kevlar. Using epoxy resin. It will be wet lay up with a light vacuum to consolidate it all. Any pointers would be great
Totally agree on not enough resin. This wasn't meant to be the first of many videos - I just was doing it to test something else and wanted to try the "sample video" format too. If I knew I would make dozens of these samples I'd have started with something more "normal" and with better technique!
Cold room and high viscosity resin? Try putting hot water in one of the mixing tubs then sit another tub with the resin stacked on top of the hot/warm water. Easier to wet out the fabric but working time may be reduced as the resin will jell quicker.
Great work! Why do you use breather and peel ply on the dry side of panel. I think they do not fulfill their function. Doesnt it work better on the wet side of panel? Thanks.
The peel ply is just to keep the breather from sticking to any exposed resin, and the breather is to spread vacuum and also protect the bag from the sharp edges of the core/wood frame. Probably would have worked ok with just peel ply but breather helps. You are right that here it doesn’t absorb excess resin. This is an example of a cheap fast way to do this but it is in no way the best way to do it!
I am not sure I understand the exact issue - does too much resin bleed out, or is it migrating under the bag to places you don't want it (where?) leaving dry areas? A couple of ideas: 1. Perforated release film (hole patterns can sized vary by product) is necessary for limiting bleed. Laps should only be 10-15mm (1/2"). 2. Use less vacuum - half or even less can be plenty to consolidate. 3. Allow resin to start to gel (slightly) before pulling vacuum. Some wet-layup resins specify a time to first compaction or some other thing - so the resin isn't sitting uncured and very liquid for a long time under vacuum. 4. Sometimes you are best off dividing a lamination into multiple curing steps - especially if there is core or things are complicated.
Good job! But why didn't you do both sides in the same time, with the upper side under another flat plate (for example, glass)? It's just a question. I'm new in these kind of things 😉
I wanted gravity to keep the resin on the surface and not run into the honeycomb. You can do it one shot and people do this often... but here I was going for absolute minimum (too little!) resin and a shiny surface on both sides. See this other one: th-cam.com/video/5h4JT1ggvX8/w-d-xo.html
Thanks for the videos! I have been watching them and was wondering what you are using for a surface/table in these layups. In other videos you say "I put it right on the teflon" - are you using a teflon board or something coated with teflon? Do you have somewhere in the videos or on your site that talks about the tables/surface you are using for these panel layups?
This is a Solvay Vac-Seal 2042 - a pretty standard type of vacuum bagging sealant tape. Plenty of other manufacturers (Airtech, General Sealants, etc.) make it and it comes in different heat tolerances and sticky-ness. It can be bought from pretty much any seller of composites vacuum bagging supplies. It isn't super cheap but it works great. There are metal roof sealant tapes that work too - they may even be the same material - but you want the 3mm thick x 12mm wide stuff - the thinner material doesn't work as well.
hi, thank you for the video. But I am trying to use honeycomb with PTFE coated fabrics? In this case which method I shall prefer? Please advise an adhesive that bonds the honeycomb with PTFE coated fabrics. Please advise. Thanks in advance
I have no idea how to glue PTFE film - I only ever use it to make things NOT stick! Is that even possible? Cyanoacrylate glues may work but I have no experience with them... what are you building?
I’m looking to build a rigid panel for camper shell. What would you recommend for the core material? Most panels will be carbon, but I’m just clueless on what core material would be best
It depends on lots of things. Is it just a shell or does it provide insulation? Curvature and span between supports is important. My guess is a 12mm / 0.5” light foam core (a recycled PET or a PVC about 50-80kg/m2or 3-5lb / ft2) with light carbon skins would be a good start. Make some tests and beat them up!
Do you mean on the tape face? Yes that would work ok for panels you want to bond to. Not shiny! Check out Laminate Sample #41 - it's really light and done in one shot but the plastic method shown would work for peel ply too as a first light ply.
I meant that that piece of Nomex is of a density that is 40kg per cubic meter - but yes, the little piece is light! And the reason to do both sides it to see how it comes out... which in this case isn't ideal.
@@MaartenOosterbaan I was trying to get two "finished" sides - but I only got two pin-hole filled but flat sides. With honeycomb cores and thin skins, the bag side laminate gets pushed into the holes in the honeycomb leaving a dimpled (and rough from peel ply) surface. Also resin in the "top" skin can drain out into the honeycomb cells leaving the laminate dry.
That weight isn't bad. By comparison, a sandwich of 9-oz fiberglass skins and 1/2" tongue-and-groove red cedar weighs in about right at one pound to the square foot. I'd be interested in doing destructive testing on both panels-- but (exclusive of cost) it's hard to imagine a better stiffness-to-weight ratio than you've got there.
There's a cedar sample in here somewhere but it's heavy compared to the carbon/nomex. In a boat, I'd rather have cedar and fiberglass between me and the ocean!
I am not a fan of heating resin unless the tooling is also heated because once the resin hits the mold it will cool off. Thermal mass issue. In many of the newer samples I use a heated table.
See sample #46 for one way - cutting back the core and back-filling with thickened resin. You can laminate some kind of capping and closeout plies over the edge tying the skins together.
Yes, need to figure out how to do this - it happens in some of the later samples. This was my first ever sample and the format has evolved. The panel is very stiff but pretty easy to dent.
If you want lowest resin to fiber ratio in a wet layup you should have a layer of breather cloth under the wet side, so you'd need to use peel ply as well. You won't get a shiny surface finish so you'd have to wet sand and polish for that. I use this method often and get 38% resin to fiber ratio. Why are you using massive pleats on a flat panel? Totally unnecessary on flat panels, also looks like you are using Stretchlon bag film anyway. Try bagging a panel without pleats, I do this with regular film and have no issues. You are cutting the panel down anyway to remove the battens, any bridging you get will only be at the outer edges anyway.
The goal here was to try to get two molded sides - makes no sense to put breather and peel ply against a tooled surface. Polishing and wet sanding is work! You’re right on the pleats being big but I wouldn’t skip them even on a thin panel - you can do as you say with very thin panels and I do in other sample videos. Bag film is standard nylon - not a fan of Stretchlon in general!
Amazing material. Thanks for showing me how its made.
This is just one way - and not the standard one. Usually honeycombs are used with pre-pregs. This method does work pretty well though for lightly loaded panels - and is way less trouble and way cheaper. Glad you found the video useful!
@@ExploreComposites Enjoy your videos but would be good if you had a consistent testing process when finished even if fairly simple like one I saw you did with a deflection test, the break test showing how a narrow sample fails. Maybe an impact test. I’m trying to work out what materials to make a lightweight, stiff hardtop for a car. But won’t be dangerous in a roll over like an only carbon one would be. But also something not too crazy on the cost. I’m angling towards a lunate of 210g kevlar with a 6mm thermhex core and another 210g kevlar on the inside with some addition bracing added afterwards of just some simple ribs of something lightweight with a couple of layers of the 210g Kevlar. Using epoxy resin. It will be wet lay up with a light vacuum to consolidate it all. Any pointers would be great
Love your videos. Is the porosity caused by the vacuum drawing through the individual cells?? Seems like it would draw the resin up into the cells. I’m clearly missing something but I’m extremely curious as to what. Thanks.
The porosity is mostly because the resin was very thick and I didn't use enough and didn't roll it out with a bubble-popper. Slightly more resin would make a big difference in to porosity! The resin will wick up the cell walls and make nice bonding "fillets" but it won't make it up to the top skin or bleed off. This is a strange way to make a panel and was kind of an experiment but it has its drawbacks.
Enjoy your videos but would be good if you had a consistent testing process when finished even if fairly simple like one I saw you did with a deflection test, the break test showing how a narrow sample fails. Maybe an impact test. I’m trying to work out what materials to make a lightweight, stiff hardtop for a car. But won’t be dangerous in a roll over like an only carbon one would be. But also something not too crazy on the cost. I’m angling towards a lunate of 210g kevlar with a 6mm thermhex core and another 210g kevlar on the inside with some addition bracing added afterwards of just some simple ribs of something lightweight with a couple of layers of the 210g Kevlar. Using epoxy resin. It will be wet lay up with a light vacuum to consolidate it all. Any pointers would be great
Exelente trabajo
Fantastic
Layup to dry and not enough resin. The core absorbed any residual resin resulting in dry CF finish. Enjoying the videos , thanks
Totally agree on not enough resin. This wasn't meant to be the first of many videos - I just was doing it to test something else and wanted to try the "sample video" format too. If I knew I would make dozens of these samples I'd have started with something more "normal" and with better technique!
Cold room and high viscosity resin? Try putting hot water in one of the mixing tubs then sit another tub with the resin stacked on top of the hot/warm water. Easier to wet out the fabric but working time may be reduced as the resin will jell quicker.
Yes, any heat would have helped! In later samples I added a heated table.
Great work! Why do you use breather and peel ply on the dry side of panel. I think they do not fulfill their function. Doesnt it work better on the wet side of panel? Thanks.
The peel ply is just to keep the breather from sticking to any exposed resin, and the breather is to spread vacuum and also protect the bag from the sharp edges of the core/wood frame. Probably would have worked ok with just peel ply but breather helps. You are right that here it doesn’t absorb excess resin. This is an example of a cheap fast way to do this but it is in no way the best way to do it!
@@ExploreComposites Ok thank you. Nice video.
My porosity problems seam to occur because of the bleeding of the resin into all the areas that are under vacuum. Do you have any tips regarding that?
I am not sure I understand the exact issue - does too much resin bleed out, or is it migrating under the bag to places you don't want it (where?) leaving dry areas? A couple of ideas:
1. Perforated release film (hole patterns can sized vary by product) is necessary for limiting bleed. Laps should only be 10-15mm (1/2").
2. Use less vacuum - half or even less can be plenty to consolidate.
3. Allow resin to start to gel (slightly) before pulling vacuum. Some wet-layup resins specify a time to first compaction or some other thing - so the resin isn't sitting uncured and very liquid for a long time under vacuum.
4. Sometimes you are best off dividing a lamination into multiple curing steps - especially if there is core or things are complicated.
@@ExploreComposites thank you very much for the detailed response. I will try your Tipps in the next laminations. Thanks again
Good job! But why didn't you do both sides in the same time, with the upper side under another flat plate (for example, glass)? It's just a question. I'm new in these kind of things 😉
I wanted gravity to keep the resin on the surface and not run into the honeycomb. You can do it one shot and people do this often... but here I was going for absolute minimum (too little!) resin and a shiny surface on both sides. See this other one: th-cam.com/video/5h4JT1ggvX8/w-d-xo.html
Thanks for the videos! I have been watching them and was wondering what you are using for a surface/table in these layups. In other videos you say "I put it right on the teflon" - are you using a teflon board or something coated with teflon? Do you have somewhere in the videos or on your site that talks about the tables/surface you are using for these panel layups?
It is a carbon table with a layer of adhesive teflon film. More here: explorecomposites.com/articles/tooling/adhesive-teflon-its-awesome/
Thank you
I'm glad you found something useful!
what's tape used for sealing? it's look reused for many vacuum process
This is a Solvay Vac-Seal 2042 - a pretty standard type of vacuum bagging sealant tape. Plenty of other manufacturers (Airtech, General Sealants, etc.) make it and it comes in different heat tolerances and sticky-ness. It can be bought from pretty much any seller of composites vacuum bagging supplies. It isn't super cheap but it works great.
There are metal roof sealant tapes that work too - they may even be the same material - but you want the 3mm thick x 12mm wide stuff - the thinner material doesn't work as well.
hi, thank you for the video. But I am trying to use honeycomb with PTFE coated fabrics? In this case which method I shall prefer? Please advise an adhesive that bonds the honeycomb with PTFE coated fabrics. Please advise. Thanks in advance
I have no idea how to glue PTFE film - I only ever use it to make things NOT stick! Is that even possible? Cyanoacrylate glues may work but I have no experience with them... what are you building?
I’m looking to build a rigid panel for camper shell. What would you recommend for the core material? Most panels will be carbon, but I’m just clueless on what core material would be best
It depends on lots of things. Is it just a shell or does it provide insulation? Curvature and span between supports is important. My guess is a 12mm / 0.5” light foam core (a recycled PET or a PVC about 50-80kg/m2or 3-5lb / ft2) with light carbon skins would be a good start. Make some tests and beat them up!
@@ExploreComposites okay thank you. Was looking for a good jumping off point and that will work!
i wonder if 4.5 to 5 o of resin would have worked better on each side ...
Peel-Ply is to go up against the wet carbon for a clean surface finish.
Do you mean on the tape face? Yes that would work ok for panels you want to bond to. Not shiny!
Check out Laminate Sample #41 - it's really light and done in one shot but the plastic method shown would work for peel ply too as a first light ply.
guessing u meant 40 grams, not 40 kilograms...? no way that bit of nomex was 40kg...btw, any reason why you would do both sides of carbon in 1 go?
I meant that that piece of Nomex is of a density that is 40kg per cubic meter - but yes, the little piece is light! And the reason to do both sides it to see how it comes out... which in this case isn't ideal.
that makes way more sense indeed...I actually meant to ask was why do both sides separately and not 1 on lay-up? @@ExploreComposites
@@MaartenOosterbaan I was trying to get two "finished" sides - but I only got two pin-hole filled but flat sides. With honeycomb cores and thin skins, the bag side laminate gets pushed into the holes in the honeycomb leaving a dimpled (and rough from peel ply) surface. Also resin in the "top" skin can drain out into the honeycomb cells leaving the laminate dry.
ah, ok...well better to be safe than sorry...no cheap materials...@@ExploreComposites
That weight isn't bad. By comparison, a sandwich of 9-oz fiberglass skins and 1/2" tongue-and-groove red cedar weighs in about right at one pound to the square foot. I'd be interested in doing destructive testing on both panels-- but (exclusive of cost) it's hard to imagine a better stiffness-to-weight ratio than you've got there.
There's a cedar sample in here somewhere but it's heavy compared to the carbon/nomex. In a boat, I'd rather have cedar and fiberglass between me and the ocean!
why are you not heating your resin if you are worried about it being thick?
I am not a fan of heating resin unless the tooling is also heated because once the resin hits the mold it will cool off. Thermal mass issue. In many of the newer samples I use a heated table.
I also done the similar test board, it's very strong. But the next question for me is: how to close the cell at the edge? 😂
See sample #46 for one way - cutting back the core and back-filling with thickened resin. You can laminate some kind of capping and closeout plies over the edge tying the skins together.
Coulda shook the panel or tried to bend it for us to see. But thanks for the idea for the core
Yes, need to figure out how to do this - it happens in some of the later samples. This was my first ever sample and the format has evolved.
The panel is very stiff but pretty easy to dent.
@@ExploreComposites nice man! Thanks for your work
If you want lowest resin to fiber ratio in a wet layup you should have a layer of breather cloth under the wet side, so you'd need to use peel ply as well. You won't get a shiny surface finish so you'd have to wet sand and polish for that. I use this method often and get 38% resin to fiber ratio. Why are you using massive pleats on a flat panel? Totally unnecessary on flat panels, also looks like you are using Stretchlon bag film anyway. Try bagging a panel without pleats, I do this with regular film and have no issues. You are cutting the panel down anyway to remove the battens, any bridging you get will only be at the outer edges anyway.
The goal here was to try to get two molded sides - makes no sense to put breather and peel ply against a tooled surface. Polishing and wet sanding is work! You’re right on the pleats being big but I wouldn’t skip them even on a thin panel - you can do as you say with very thin panels and I do in other sample videos. Bag film is standard nylon - not a fan of Stretchlon in general!
Say no to pinholes. They are ugly and each one is a point of failure
I agree they’re ugly and lots of work to fill! Not sure they make it measurably weaker in this case though…