vacuum setup.pdf (52.2 KB)
Hi
Just wanted to check if you feel anything is wrong with this setup.
Do you have any recomendation for the tubing? Is the tubing between mold and resin pot and the rest of the setup, different? (I understand it should be disposable as it fills with epoxy). Do all tubes work well with resin line clamps?
Thanks
I am not sure about your resin lines, but if you want to rig things such that you can put vacuum on the resin feed, you just should add a resin feed line from the T-joint in the resin line into a bucket, and rigged with a clamp.
During infusion, the clamp to the catchpot is clamped, and the clamp to the resin bucket is open. After infusion, the clamp to the resin bucket is closed, and the one to the catch pot is open. after infusion, bring back vacuum to 50 mbar abs (-950 mbar) at least, to allow voids to “implode”.
Your spare pump setup is smart. If your pump breaks down, your part is not lost.
i am preparing my infrastructure to infuse a wing skin. so loosing 7 m2 of carbon laminate deserves the inclusion of a spare pump and an emergency manual with plan B and C for things that could go wrong. I would also like to be able to apply vacuum to the resin pot.
My resin catch pot is a big painting pressure container. I also have a broken compressor and therefor a pressure tank. Would the compressor tank add some quality to the setup to normalize the vacuum?
Can I do something wrong with the vaccum tubing? Is spray gun tubing a good solution?
The compressor tank is not necessary but will help if your pump dies during the infusion.
The “best” vacuum tubing in my opinion is the cheapest tubing that will not collapse under full vacuum. I typically use LLDPE (linear low-density polyethylene) tubing purchase from McMaster Carr (5181K26) at $0.28 per foot.
My doubt was mainly regarding colapse.
I have worked a lot with vaccum bagging and never with infusion.
I am really not able to evaluate the strength of full vacuum. I am also thinking about staying open to heat up the mold (maybe 100º) and weakening with the heat the tube.
What diameter would you recommend? I will infuse a wing mold (7m2). A 12mm inner diameter? What happens if I clamp a polyethylen tube. When pressed is the tube damaged and weakend against collapse? My pump is 8CFM.
What about the tubing from the resin pot to the mold? Is it wasted with every infusion?
The special vaccum hoses with metal spirals cost a little fortune.
I liked silicone tubing on ebay. (heat resistant)
Thanks for your tips
Sorry, I failed to notice that you are located in Madrid. 10 mm I.D. should be sufficient but going larger should not cause problems except waste a bit more resin.
You can clamp and re-open LLDPE tubing without any problems.
The tube from the resin pot to the mold will be wasted with each infusion.
I suggest using the cheapest tubing and do a practice run using fiberglass in place of carbon. This will allow you to test your setup and identify any problems before you use carbon.
Yes of course I will do several glassfiber test sections before touching any carbon. I
need anyway to test my approach to infusing sandwich structures. Currently I am thinking about a 3 stage layup.
1 Infuse the outer skin to the mold side.
2 Glue the foam or closed honeycomb
3 Infusing the inner skin
One step perforated sandwich foams are to heavy and an impregnation failure isnt easy to recognize.
Didnt thought about the resin waste. I will stick to 10mm ID.
Does an excesssively wide spiral tube also imply a lot of resin waste? What width would you recommend for a 6m x 1,2m mold? By the way how many resin inlets would you recommend at what spacing feeding thru a central resin feed line lengthwise?