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Old 06-18-2014, 08:14 PM   #1
raxton

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Default Carbon Fiber Perfect Finish

Hello, I have been testing panels using VARTM and most come out ok. Then one day I pulled a panel and to my surprise the carbon fiber looked simply amazing in comparison to other panels previously done.

So I have researched and read about it as I am somewhat new to composites but have really been doing my homework. The answers I have found seen to be its beautiful finish being purely based on resin content being more rich than previous panels.

I am looking for a way to achieve this in every panel I infuse. Here are a couple of pictures for example.

This panel is a single layer of 6k cf using epoxy resin. With normal vacuum infusion stack. reinforcement/peel ply/green mesh.

[IMG][/IMG]

this is a panel of a 7.5oz with a soric xf core. As you can see the look changes at about 1 inch from top of panel. That is where the soric stopped and was just a peel ply break.

[IMG][/IMG]

Any helpful advice would be great as 8 out of 10 various panels have the carbon fiber pressed looking effect.

I just ordered some MTI hose to test out.

I have also ordered some RED infusion mesh as someone has said on here that they received better cosmetic parts with it.

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Old 06-18-2014, 11:57 PM   #2
Michiel

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Do you degas your resin ? Were do you put the resin pot while infusion ? For cosmetic parts there be a lot more resin in it. Both panels have a to low vf for cosmetic parts. Make a brake zone that's smaller on the part and a part off the product. Degas resin if you didn't do that already, put the resin pot at the same hight as your infusion and try to slow down your infusion. The green flow mesh is in overall to fast.
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Old 06-19-2014, 05:06 AM   #3
sammymatik

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Quote:
Originally Posted by Michiel View Post
put the resin pot at the same hight as your infusion and try to slow down your infusion. The green flow mesh is in overall to fast.
If you put the resin pot on the table or above, you're gonna flow resin faster.

Also, how long do you leave the part under vacuum before infusing?

I"ve had fine results without degassing, i'm sure it's better to do so. What I find is that having a good break area seems to be a big factor.

Infusion is a little tricky until you get your setup nailed down.
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Old 06-19-2014, 08:29 AM   #4
raxton

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Quote:
Originally Posted by Michiel View Post
Do you degas your resin ? Were do you put the resin pot while infusion ? For cosmetic parts there be a lot more resin in it. Both panels have a to low vf for cosmetic parts. Make a brake zone that's smaller on the part and a part off the product. Degas resin if you didn't do that already, put the resin pot at the same hight as your infusion and try to slow down your infusion. The green flow mesh is in overall to fast.
can you explain that part i put in bold, please.

are you saying both panels do not have enough resin in them for the volume fraction and need to be more resin rich for a cosmetic part.

I will really add a nice brake zone, but yes I am putting the resin pot right next to the part on the table to pump more resin in. I ordered some red mesh so hopefully that helps too.

I have tried contacting lantor to order some soric tf but they have not got back to me. anyone know where to purchase that in the US. And since its such a resin rich layer I thought it would help wet out my bottom reinforcement.

thanks for your responses

Last edited by raxton; 06-19-2014 at 08:35 AM.
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Old 06-19-2014, 08:38 AM   #5
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Quote:
Originally Posted by sammymatik View Post
If you put the resin pot on the table or above, you're gonna flow resin faster.

Also, how long do you leave the part under vacuum before infusing?

I"ve had fine results without degassing, i'm sure it's better to do so. What I find is that having a good break area seems to be a big factor.

Infusion is a little tricky until you get your setup nailed down.
I usually do a drop test of about 20-30 minutes before infusing.

I built a degassing chamber but it is only 8 inch and was too small to degas the amount of resin I am needing so I headed the resin up a bit to free some bubbles. I wasn't to worried about little pin holes due to it being a test panel and knowing my resin had air still in it.

I will do like you said and add a better brake in it, hopefully the MTI hose will help out too.

Yea I cant wait to get it down so that I can start doing it will consistency.
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Old 06-19-2014, 12:55 PM   #6
Michiel

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Quote:
Originally Posted by sammymatik View Post
If you put the resin pot on the table or above, you're gonna flow resin faster.

Also, how long do you leave the part under vacuum before infusing?

I"ve had fine results without degassing, i'm sure it's better to do so. What I find is that having a good break area seems to be a big factor.

Infusion is a little tricky until you get your setup nailed down.
Yes, but there are ways to slow down the infusion. It's a combination that is needed here.
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Old 06-19-2014, 12:55 PM   #7
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Quote:
Originally Posted by raxton View Post
can you explain that part i put in bold, please.

are you saying both panels do not have enough resin in them for the volume fraction and need to be more resin rich for a cosmetic part.

I will really add a nice brake zone, but yes I am putting the resin pot right next to the part on the table to pump more resin in. I ordered some red mesh so hopefully that helps too.

I have tried contacting lantor to order some soric tf but they have not got back to me. anyone know where to purchase that in the US. And since its such a resin rich layer I thought it would help wet out my bottom reinforcement.

thanks for your responses
It needs more resin for cosmetic use.
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Old 06-19-2014, 03:44 PM   #8
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I've had mixed results using a brake zone with mti hose. On flat panels it worked well because the resin front was equal. But on more complex parts where the resin doesn't flow completely even, it can cause problems. If the resin reaches one part of the mti hose before the rest of the flow front, then it will race along the membrane faster than it will flow through the dry brake zone, and you can end up with dry spots of brake zone that take an age to wet out. Meanwhile the rest of your part is getting way too resin rich. But if you clamp your resin line before the peel ply is fully wet out then it can leach resin from your laminate and you end up with pinholes again.
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Old 06-19-2014, 08:17 PM   #9
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how would you make a part more resin rich in infusion? Isnt the point of infusion to create a close-to perfect ratio of resin to fiber?

How long should you leave the part under vacuum for before introducing resin? When i leave it for 10-15 minutes it really flattens the look of the weave..

OP- are the pics you posted with or without a gel coat?
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Old 06-19-2014, 10:40 PM   #10
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Quote:
Originally Posted by Hanaldo View Post
I've had mixed results using a brake zone with mti hose. On flat panels it worked well because the resin front was equal. But on more complex parts where the resin doesn't flow completely even, it can cause problems. If the resin reaches one part of the mti hose before the rest of the flow front, then it will race along the membrane faster than it will flow through the dry brake zone, and you can end up with dry spots of brake zone that take an age to wet out. Meanwhile the rest of your part is getting way too resin rich. But if you clamp your resin line before the peel ply is fully wet out then it can leach resin from your laminate and you end up with pinholes again.
+1 on this. I've experienced this as well when using a brake zone with MTI hose. My brake zone is too small to actually leach enough resin out of my part to create any noticeable pinholes, even after clearing, but I've definitely noticed a sealed hose and a delayed wet out of random parts of my peel ply in the brake zone. But god damn, does the MTI hose work wonders or what
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