Talk Composites - The Forum for Advanced Composites
Back
Login
Register
Login
Register
Home
»
Advanced Composites Forum
»
Resin Infusion
»
First infusion has porosity
First infusion has porosity
Post Reply
Like
6
First infusion has porosity
View
Flat Ascending
Flat Descending
Threaded
Options
Subscribe to topic
Print This Topic
Goto Topics Forum
Author
Message
Roo2
Roo2
posted 8 Years Ago
ANSWER
HOT
Topic Details
Group: Forum Members
Posts: 8,
Visits: 31
Hello there,
I've just completed my first infused part. It's a shell for a home made metal detector coil. I'm generally happy with the result but would like to improve the surface finish on future parts.
The part is made with 2 layers of 200gsm fibreglass and a low viscosity epoxy that uses a very slow hardener. It took over 4 hours to start to gel in a warm environment. I'm using a pump that can get down to about -28" and after I infused the resin it was turned off. No evidence of leaks where seen and the vacuum gauge needle didn't move for the entire cure duration.
If you look at the attached photo of the shell on the scales there are a few areas that appear to have porosity. Small holes between the fibre weave. Could that be caused by using hardener that is too slow and all the resin has been squeezed, drawn out of the very thin laminate? Or is it just evidence of tiny air leaks I couldn't see or measure?
Thanks
Attachments
IMG_2461.JPG
(
546 views,
1.00 MB
)
IMG_2463.JPG
(
452 views,
2.00 MB
)
Reply
Like
6
GO
Merge Selected
Merge into selected topic...
Merge into merge target...
Merge into a specific topic ID...
Open Merge
Threaded View
Threaded View
First infusion has porosity
Roo2
-
8 Years Ago
Did you degas your resin? If not, that will very likely cause the problems.
oekmont
-
8 Years Ago
Hmm. No I didn't degas. The resin I used was quite runny and I didn't stir it vigorously. I didn't...
Roo2
-
8 Years Ago
With a long pot life what you can do is leave the resin to stand for 10 minutes before infusing as...
Warren (Staff)
-
8 Years Ago
In my opinion a really perfect finish could only be achieved with a properly degassed resin. During...
oekmont
-
8 Years Ago
Degassing is totally unnecessary for a perfect cosmetic finish, I do it day in day out and never...
Hanaldo
-
8 Years Ago
I can definitely say that degassing could be a very important part of the infusion process. Maybe it...
oekmont
-
8 Years Ago
I guess degassing may depend on the resin and how you stir it up- if you trap a lot of air. I...
polaraligned
-
8 Years Ago
Thanks for all the feedback. I'll try both allowing the resin to stand and degassing in the resin...
Roo2
-
8 Years Ago
If you're mould was porous, you'd definitely see evidence of air ingress during the infusion As...
MarkMK
-
8 Years Ago
If you do a corret degassing (proper chamber, full vacuum) you'll notice that even a crystal clear...
oekmont
-
8 Years Ago
Well water at a molecular level is a product of oxygen and hydrogen, so of course there will always...
Hanaldo
-
8 Years Ago
Thanks all. I have a small fiddly part to infuse this weekend. I'll use my runny slow cure resin and...
Roo2
-
8 Years Ago
The mentioned effect has nothing to do with the oxygen bound in the water molecules. Although water...
oekmont
-
8 Years Ago
I used my resin trap to degas a small batch of resin in a cup. It formed a nice frothy head that...
Roo2
-
8 Years Ago
Also remember there will be some small amount of air in the fabric that comes out during the...
Warren (Staff)
-
8 Years Ago
Post Reply
Like
6
Similar Topics
Post Quoted Reply
Reading This Topic
Login
Login
Remember Me
Reset Password
Resend Validation Email
Login
Facebook
Google
Explore
Messages
Mentions
Search