Hi guys, I'm doing some infusion tests with carbon twill 3k at low cost and I have problems
because the result is always the same getting dry finish on the surface.

I tried some methods like closing the vacuum line and then making the piece rich in resin, but nothing, it's always the same ..

Resin pot line: 6mm full open, fast.
Test 1: 30 seconds
Test 2: 1 minute
Test 3: 1 minute 30 seconds
Test 4: 2 minutes
Test 5: 4 minutes
Test 6: 8 minutes

Always the same, dry spots.


Testing on glass, plain..
Infusion area: 25x30cm - Carbon area: 15cm x 20cm

Im using the entire vacuum infusion kit from easycomposites, but not:
-Carbon Fiber
-Vacuum bag.
-Peel ply
-Epoxy Resin A+B = 400cps.

Any comments will be appreciated, thank you.

What are your leak tests like? 

It sounds like you are doing something fundamentally wrong if you have the same fault despite changing other variables.

What is your exact bagging stack and sequence  for the infusion?


Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

4 coats of wax - meguiars mold release n8. (Coat1 35min+10min shine>repeat) after the final coat, 1 hour to dry.
x4 15x20 cf twill 3k layers (from 1m2 at 200gr thickness 0.30mm) > x1 17x22 peel ply > x1 17x22 flow mesh > x1 25x30 vacuum bag.
1hr leak test, perfect.
-Mixing resin 2 min slowly
-Degassing 4 min
-Infusing resing 15-18 min slowly
-close vacuum line to add more resin to mould.

-room temp in all tests are 22c to 24c, pot life is 40min, mixing perfectly to 2:1 as the manufacturer says.

I do not know if I will have to change vacuum bag, the flow mesh or the carbon fiber..

NOTE: This is the cheap carbonfiber, I think this dont let me filter the resin correctly between the tissue.

That isnt dry, it's a release issue. Release waxes often dont work on glass because they struggle to bond to it. So when you buff it off, you actually remove most of the wax.

Switch to a chemical release, you wont have the same problem.

Thanks alot!

Another possibility on the same tangent; how long are you leaving it to cure before demoulding? If you're doing it slightly too early, then it can grip the mould more than usual as well.

Either way, it's a release issue.

This resin cure fast, manufacturer say 6hr, but im demoulding at 24hr, same results.

EDIT: Tested on flat mold of polyester gelcoat, its OK, thanks.

Hi guys, looks like I have another problem, my vacuum pump (dvp ec.4) emits bubbles in the oil gauge after turning it on.

Thanks.

Bubbles in the sight gauge are normal.  They tend to calm down a bit once full vacuum is achieved and there is no air exchange.  Also make sure you haven't over filled it with oil as that can make the bubbles appear worse.

Running for long periods of time, the casing  could well get up to 50C or slightly more so generally this is nothing to worry about. 

The main thing is ensure your leak tests are successful as that way you know the pump will be running against a  properly sealed bag.


Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Thanks.
One more question, is the oil separator filter washable?
I am not from Europe and it is more difficult for me to buy another, easycomposites will add it to the sale list? (DVP 1801046)

Regards.