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Damien
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Group: Forum Members
Posts: 32,
Visits: 132
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+x+x+x+xHi Zeda3000, Sorry for the late reply. I don't have a picture of the pinholes at the moment. So until now, here was my process: - Mould: I was using a black gelcoat that I bought in a composite shop for kayak builders here, backing it with glass woven and polyester resin. - Release agent: I was using either wax, or EasyLease from EC. Except recently, but that has been solved, I did not have any issue with releasing my parts. But then the issues start. Initially I was using for my carbon fiber parts a 200 gr/m2 carbon fiber cloth very similar to this: https://www.easycomposites.co.uk/honeycomb-bonding-epoxy-adhesiveMy epoxy was also epoxy sold by this kayak builder shop. It is relatively thick. I am mixing it quite well. The temperature of the room is fluctuating as I am doing this in my garage, but I tried to heat the working area as well as possible with some hot radiator. Then I apply my layers of carbon +epoxy (in a 1:1 or 1:1.2 carbon/resin ratio). Then I was using peel ply, perforated film and a breather layer (which is a bit thicker but less dense than the EC one). And then in a vacuum bag with uncontrolled vacuum (small pump with which I cannot control the vacuum. Basically, the film is really against the part and it is not easy to manually pull it away while the pump is running). I would leave the pump ON throughout the curing process. The result initially looked like I had resin starvation. Theses are lots of gaps between the carbon fibers. I was advised to limit resin flow by adding a second layer of perforated film, which helped. But nevertheless, at the end, I had still lots of small gaps...so the only method I found was to use a brush and put an extra layer of the same epoxy resin, sand (because I would still have hole and the brush does not give a nice flat surface in my hand), do it again, sand, do it again. etc...etc... this was the mots time consuming part of all. Then I was suggested to put a layer of transparent gelcoat in the mould which would be nice and uniform, let it mostly cure, and then do my carbon epoxy layup. But this never worked because that gelcoat would make massive fish eyes all over the place (whether with wax or easy lease). So I gave up on this, although I was hoping it would be the solution. Thing is that I have indeed been using chemicals (epoxy, mould gelcoat, transparent finish gelcoat, release agent etc...) for all kind of source and in particular that kayak builder shop. But it may not be the ideal stuffs for carbon parts like what I am trying to do. So now (but I have not tried yet), I have EG60 and EMP60 systems for my mould, Easy Lease for the release agent, and the EL2 laminating resin. So will see if this helps...Also I got EC breather layer. Any idea ? In the meantime, I am building myself an oven for out-of-autoclave prepreg, because I think (possibly wrongly !) that it would make my life easier and better finish right of the mould (using of course temperature resitant mould materials, resins etc...). Thanks ! This is a lot of details hard to tell or comment without see by picture. But main suggests Change your resin. Use resin suitable for infusion or hand lay up. Prefer good brand names Change your vacuum pump. Buy somehting you can control the pressure. Please consider. More pressure is meaning better surface. Sound like to me you have poor resin flow and poor pressure. Thanks a lot ! I have now the EL2 resin from Easycomposites. I also have a bit of infusion resin from sicomin that someone gave me to try. Very interesting about the pressure and pump. Do you have any vacuum values that you would consider to be good ? Do you think this pump would do ? https://www.easycomposites.co.uk/release-filmI could connect it to a vacuum regulator to have a good vacuum. Do you think that would be enough or even better pump would be necessary ? Thank you so much for all your help. First of all Vacuum pressure calculating according to your composite part size and lamination thickness. After your information i could tell you this pump will good for you or not.May i ask your part size or sample picture and what is your lamination thickness and layers. Is your process Hand lay up and vacuum press or direct infusion? I am sorry i have no clue about EL2 Resin. I am working most Professional Level Brand names. Thanks Thanks ! I only do small parts for my motorcycle. So maybe 20 inches are the largest parts I make. I don't quite have a picture at hand, but I will try to make one. For instance right now I am doing protetors for my radiator, which are 10 inches long and 2 inches wide. Thickness is from 1 mm to 6 mm max (I have made some carbon plates of 6 mm. But most of the things I do are between 1 and 3 mm thick). My process is hand layup and vacuum press. I don't do infusion (it's a bit more tricky it seems). My layup is carbon (using 200, 450 and 650 gr/m2 depending on the thickness I want), peel ply, one or two layers of perforated film and a layer of breather. This pump, however, does not come with a vacuum regulator, but this is something I can get (though it's quite expensive). But I don't know whether it's absolutely necessary for what I do...or not. Thanks again!
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zeda3000
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Group: Forum Members
Posts: 5,
Visits: 21
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+x+x+xHi Zeda3000, Sorry for the late reply. I don't have a picture of the pinholes at the moment. So until now, here was my process: - Mould: I was using a black gelcoat that I bought in a composite shop for kayak builders here, backing it with glass woven and polyester resin. - Release agent: I was using either wax, or EasyLease from EC. Except recently, but that has been solved, I did not have any issue with releasing my parts. But then the issues start. Initially I was using for my carbon fiber parts a 200 gr/m2 carbon fiber cloth very similar to this: https://www.easycomposites.co.uk/honeycomb-bonding-epoxy-adhesiveMy epoxy was also epoxy sold by this kayak builder shop. It is relatively thick. I am mixing it quite well. The temperature of the room is fluctuating as I am doing this in my garage, but I tried to heat the working area as well as possible with some hot radiator. Then I apply my layers of carbon +epoxy (in a 1:1 or 1:1.2 carbon/resin ratio). Then I was using peel ply, perforated film and a breather layer (which is a bit thicker but less dense than the EC one). And then in a vacuum bag with uncontrolled vacuum (small pump with which I cannot control the vacuum. Basically, the film is really against the part and it is not easy to manually pull it away while the pump is running). I would leave the pump ON throughout the curing process. The result initially looked like I had resin starvation. Theses are lots of gaps between the carbon fibers. I was advised to limit resin flow by adding a second layer of perforated film, which helped. But nevertheless, at the end, I had still lots of small gaps...so the only method I found was to use a brush and put an extra layer of the same epoxy resin, sand (because I would still have hole and the brush does not give a nice flat surface in my hand), do it again, sand, do it again. etc...etc... this was the mots time consuming part of all. Then I was suggested to put a layer of transparent gelcoat in the mould which would be nice and uniform, let it mostly cure, and then do my carbon epoxy layup. But this never worked because that gelcoat would make massive fish eyes all over the place (whether with wax or easy lease). So I gave up on this, although I was hoping it would be the solution. Thing is that I have indeed been using chemicals (epoxy, mould gelcoat, transparent finish gelcoat, release agent etc...) for all kind of source and in particular that kayak builder shop. But it may not be the ideal stuffs for carbon parts like what I am trying to do. So now (but I have not tried yet), I have EG60 and EMP60 systems for my mould, Easy Lease for the release agent, and the EL2 laminating resin. So will see if this helps...Also I got EC breather layer. Any idea ? In the meantime, I am building myself an oven for out-of-autoclave prepreg, because I think (possibly wrongly !) that it would make my life easier and better finish right of the mould (using of course temperature resitant mould materials, resins etc...). Thanks ! This is a lot of details hard to tell or comment without see by picture. But main suggests Change your resin. Use resin suitable for infusion or hand lay up. Prefer good brand names Change your vacuum pump. Buy somehting you can control the pressure. Please consider. More pressure is meaning better surface. Sound like to me you have poor resin flow and poor pressure. Thanks a lot ! I have now the EL2 resin from Easycomposites. I also have a bit of infusion resin from sicomin that someone gave me to try. Very interesting about the pressure and pump. Do you have any vacuum values that you would consider to be good ? Do you think this pump would do ? https://www.easycomposites.co.uk/release-filmI could connect it to a vacuum regulator to have a good vacuum. Do you think that would be enough or even better pump would be necessary ? Thank you so much for all your help. First of all Vacuum pressure calculating according to your composite part size and lamination thickness. After your information i could tell you this pump will good for you or not.May i ask your part size or sample picture and what is your lamination thickness and layers. Is your process Hand lay up and vacuum press or direct infusion? I am sorry i have no clue about EL2 Resin. I am working most Professional Level Brand names. Thanks
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Damien
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Group: Forum Members
Posts: 32,
Visits: 132
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+x+xHi Zeda3000, Sorry for the late reply. I don't have a picture of the pinholes at the moment. So until now, here was my process: - Mould: I was using a black gelcoat that I bought in a composite shop for kayak builders here, backing it with glass woven and polyester resin. - Release agent: I was using either wax, or EasyLease from EC. Except recently, but that has been solved, I did not have any issue with releasing my parts. But then the issues start. Initially I was using for my carbon fiber parts a 200 gr/m2 carbon fiber cloth very similar to this: https://www.easycomposites.co.uk/honeycomb-bonding-epoxy-adhesiveMy epoxy was also epoxy sold by this kayak builder shop. It is relatively thick. I am mixing it quite well. The temperature of the room is fluctuating as I am doing this in my garage, but I tried to heat the working area as well as possible with some hot radiator. Then I apply my layers of carbon +epoxy (in a 1:1 or 1:1.2 carbon/resin ratio). Then I was using peel ply, perforated film and a breather layer (which is a bit thicker but less dense than the EC one). And then in a vacuum bag with uncontrolled vacuum (small pump with which I cannot control the vacuum. Basically, the film is really against the part and it is not easy to manually pull it away while the pump is running). I would leave the pump ON throughout the curing process. The result initially looked like I had resin starvation. Theses are lots of gaps between the carbon fibers. I was advised to limit resin flow by adding a second layer of perforated film, which helped. But nevertheless, at the end, I had still lots of small gaps...so the only method I found was to use a brush and put an extra layer of the same epoxy resin, sand (because I would still have hole and the brush does not give a nice flat surface in my hand), do it again, sand, do it again. etc...etc... this was the mots time consuming part of all. Then I was suggested to put a layer of transparent gelcoat in the mould which would be nice and uniform, let it mostly cure, and then do my carbon epoxy layup. But this never worked because that gelcoat would make massive fish eyes all over the place (whether with wax or easy lease). So I gave up on this, although I was hoping it would be the solution. Thing is that I have indeed been using chemicals (epoxy, mould gelcoat, transparent finish gelcoat, release agent etc...) for all kind of source and in particular that kayak builder shop. But it may not be the ideal stuffs for carbon parts like what I am trying to do. So now (but I have not tried yet), I have EG60 and EMP60 systems for my mould, Easy Lease for the release agent, and the EL2 laminating resin. So will see if this helps...Also I got EC breather layer. Any idea ? In the meantime, I am building myself an oven for out-of-autoclave prepreg, because I think (possibly wrongly !) that it would make my life easier and better finish right of the mould (using of course temperature resitant mould materials, resins etc...). Thanks ! This is a lot of details hard to tell or comment without see by picture. But main suggests Change your resin. Use resin suitable for infusion or hand lay up. Prefer good brand names Change your vacuum pump. Buy somehting you can control the pressure. Please consider. More pressure is meaning better surface. Sound like to me you have poor resin flow and poor pressure. Thanks a lot ! I have now the EL2 resin from Easycomposites. I also have a bit of infusion resin from sicomin that someone gave me to try. Very interesting about the pressure and pump. Do you have any vacuum values that you would consider to be good ? Do you think this pump would do ? https://www.easycomposites.co.uk/release-filmI could connect it to a vacuum regulator to have a good vacuum. Do you think that would be enough or even better pump would be necessary ? Thank you so much for all your help.
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zeda3000
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Group: Forum Members
Posts: 5,
Visits: 21
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+xHi Zeda3000, Sorry for the late reply. I don't have a picture of the pinholes at the moment. So until now, here was my process: - Mould: I was using a black gelcoat that I bought in a composite shop for kayak builders here, backing it with glass woven and polyester resin. - Release agent: I was using either wax, or EasyLease from EC. Except recently, but that has been solved, I did not have any issue with releasing my parts. But then the issues start. Initially I was using for my carbon fiber parts a 200 gr/m2 carbon fiber cloth very similar to this: https://www.easycomposites.co.uk/honeycomb-bonding-epoxy-adhesiveMy epoxy was also epoxy sold by this kayak builder shop. It is relatively thick. I am mixing it quite well. The temperature of the room is fluctuating as I am doing this in my garage, but I tried to heat the working area as well as possible with some hot radiator. Then I apply my layers of carbon +epoxy (in a 1:1 or 1:1.2 carbon/resin ratio). Then I was using peel ply, perforated film and a breather layer (which is a bit thicker but less dense than the EC one). And then in a vacuum bag with uncontrolled vacuum (small pump with which I cannot control the vacuum. Basically, the film is really against the part and it is not easy to manually pull it away while the pump is running). I would leave the pump ON throughout the curing process. The result initially looked like I had resin starvation. Theses are lots of gaps between the carbon fibers. I was advised to limit resin flow by adding a second layer of perforated film, which helped. But nevertheless, at the end, I had still lots of small gaps...so the only method I found was to use a brush and put an extra layer of the same epoxy resin, sand (because I would still have hole and the brush does not give a nice flat surface in my hand), do it again, sand, do it again. etc...etc... this was the mots time consuming part of all. Then I was suggested to put a layer of transparent gelcoat in the mould which would be nice and uniform, let it mostly cure, and then do my carbon epoxy layup. But this never worked because that gelcoat would make massive fish eyes all over the place (whether with wax or easy lease). So I gave up on this, although I was hoping it would be the solution. Thing is that I have indeed been using chemicals (epoxy, mould gelcoat, transparent finish gelcoat, release agent etc...) for all kind of source and in particular that kayak builder shop. But it may not be the ideal stuffs for carbon parts like what I am trying to do. So now (but I have not tried yet), I have EG60 and EMP60 systems for my mould, Easy Lease for the release agent, and the EL2 laminating resin. So will see if this helps...Also I got EC breather layer. Any idea ? In the meantime, I am building myself an oven for out-of-autoclave prepreg, because I think (possibly wrongly !) that it would make my life easier and better finish right of the mould (using of course temperature resitant mould materials, resins etc...). Thanks ! This is a lot of details hard to tell or comment without see by picture. But main suggests Change your resin. Use resin suitable for infusion or hand lay up. Prefer good brand names Change your vacuum pump. Buy somehting you can control the pressure. Please consider. More pressure is meaning better surface. Sound like to me you have poor resin flow and poor pressure.
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Damien
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Group: Forum Members
Posts: 32,
Visits: 132
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Hi Zeda3000, Sorry for the late reply. I don't have a picture of the pinholes at the moment. So until now, here was my process: - Mould: I was using a black gelcoat that I bought in a composite shop for kayak builders here, backing it with glass woven and polyester resin. - Release agent: I was using either wax, or EasyLease from EC. Except recently, but that has been solved, I did not have any issue with releasing my parts. But then the issues start. Initially I was using for my carbon fiber parts a 200 gr/m2 carbon fiber cloth very similar to this: https://www.easycomposites.co.uk/honeycomb-bonding-epoxy-adhesiveMy epoxy was also epoxy sold by this kayak builder shop. It is relatively thick. I am mixing it quite well. The temperature of the room is fluctuating as I am doing this in my garage, but I tried to heat the working area as well as possible with some hot radiator. Then I apply my layers of carbon +epoxy (in a 1:1 or 1:1.2 carbon/resin ratio). Then I was using peel ply, perforated film and a breather layer (which is a bit thicker but less dense than the EC one). And then in a vacuum bag with uncontrolled vacuum (small pump with which I cannot control the vacuum. Basically, the film is really against the part and it is not easy to manually pull it away while the pump is running). I would leave the pump ON throughout the curing process. The result initially looked like I had resin starvation. Theses are lots of gaps between the carbon fibers. I was advised to limit resin flow by adding a second layer of perforated film, which helped. But nevertheless, at the end, I had still lots of small gaps...so the only method I found was to use a brush and put an extra layer of the same epoxy resin, sand (because I would still have hole and the brush does not give a nice flat surface in my hand), do it again, sand, do it again. etc...etc... this was the mots time consuming part of all. Then I was suggested to put a layer of transparent gelcoat in the mould which would be nice and uniform, let it mostly cure, and then do my carbon epoxy layup. But this never worked because that gelcoat would make massive fish eyes all over the place (whether with wax or easy lease). So I gave up on this, although I was hoping it would be the solution. Thing is that I have indeed been using chemicals (epoxy, mould gelcoat, transparent finish gelcoat, release agent etc...) for all kind of source and in particular that kayak builder shop. But it may not be the ideal stuffs for carbon parts like what I am trying to do. So now (but I have not tried yet), I have EG60 and EMP60 systems for my mould, Easy Lease for the release agent, and the EL2 laminating resin. So will see if this helps...Also I got EC breather layer. Any idea ? In the meantime, I am building myself an oven for out-of-autoclave prepreg, because I think (possibly wrongly !) that it would make my life easier and better finish right of the mould (using of course temperature resitant mould materials, resins etc...). Thanks !
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zeda3000
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Group: Forum Members
Posts: 5,
Visits: 21
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Small Bubbels or pin holes could be from couple of diffrent reasons.
1- Bad mixture
2- High or low room temperature
3- Too much resin flow in surface
4- Wrong resin
5- Low pressure
If you could share the picture your pin holes or bubbles and also list of your composite materials. I think i can give more detailed information.
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Damien
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Group: Forum Members
Posts: 32,
Visits: 132
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Dear all,
Ok, making progress ! I am going to do some pre-preg in the near future, but not quite tomorrow, because the build up of my oven is delayed due to the lockdown...
Now question about the finish...I am pretty OK with making molds of relatively complicated parts. I use hand layup then vacuum bagging, and all this works pretty smoothly. THe parts I build are quite OK, but the finish is not so very good. I always have some small bubbles or so that force me to brush another layer of epoxy at the top, then sand, then brush epoxy again...this is what takes most of my time when making parts, and it is pretty frustrating. I know that one can reach perfect finish right out of the mold, but I cannot work in the conditions to do so. I am just doing stuffs for myself, in my garage...so nothing really optimal and I think I have to live with not prefect out-of-the-mold finish. Now when I apply some epoxy coat on the parts, it is also incredibly frustrating, because with the brush, even at good temperature, it's never really flat. And also it is thicker at the edges, making the subsequent sanding a real pain. Any advice ? I was considering using an airbrush to spray very thin layers of car varnish (I am only doing small parts, so the airbrush is good enough). Or is it a bad idea ? I see people using an epoxy gelcoat in the mould for make the very good surface...but I tried something like that and with the release agent, I don't manage to get that gelcoat smooth on the surface, it makes massive fish eyes all over the place... Anyway, if someone has a relatively simple solution for me to make part finish easier, that would be soooooo helpful, because I am getting really fed up of spending so much time sanding/brushing/sanding etc...all this to get something that is not perfect either.
Finally, a need to make parts that are smooth on both sides. So I was thinking of using a mould / counter-mould approach. But how does one make sure that there is no big air bubble trapped between the carbon and the counter-mould ?
Thank you !
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