Lots of holes in Stretchlon film when infusing

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#1

I am hoping to get some input from the experienced people on here. I started my first infusion last night. It’s actually still on the vacuum and should be done around 7pm EST this evening.

I was never able to get a perfect vacuum after clamping off the vacuum line but I was able to get the gauge to read about -30 so I figured I would go ahead and do the infusion. After pulling resin for about 5 minutes the pressure changed and I could hear a hold in the bag (no around the pleats or edges) and for the next 2 hours I was constantly checking and fixing holes. Is this normal? I am using Stretchlon vacuum film.

I have attached a few pictures of the mold as it sits now. I had to use a ton of tape to seal the holes because I couldn’t find the first few (must have been really small). All together I had about 5-6 holes in the bag. I was able to leave it running all night and when I woke up this morning there pressure was still around -29.

Is Stretchlon is not the best film? Am I not making enough pleats? Does anyone notice anything I am doing incorrectly?

Thanks in advance!

#2

Oh wow if all that white is vac bagging tape that is a lot of holes. If that’s the case there shouldn’t be that many holes in the middle of the bag. Was it stored badly or abused?

Also it looks like your part is flat. I would suggest using some other bagging material like Wrightlon instead since it’s cheaper and much easier to handle.

#3

Well all that tape covers about 6 holes. I couldn’t find the holes in the center so I just had to lay down tape where I thought I heard the air coming from.

I bought the film from AircraftSpruce in GA and it was put on a roll for me. I don’t believe it was damaged at all.

The interesting thing was that the holes didn’t appear until I was well into the infusion process. After I fixed the first hole I didn’t notice another once for about 30 minutes, then 30 minutes after that a couple more holes appeared. It almost seems like the bag is getting torn by the infusion mesh, but I really don’t know.

#4

you should be doing leak checks prior to infusing, just cause your gauge reads “30” doesnt mean anything. Those types of gauges are never correct and is irrelevant to if you have a leak or not. 99.9% of holes in a decent quality bag film is from poor handling.

#5

Is there a way to check the film before using it to see if its damaged? I just bought 10 yards of Stretchlon and have tried vacuuming this tool 3 times, each time I could never get 100% sealed vacuum. I am guessing now that the film is damaged.

Is Stetchlon film more easily damaged than the thicker more brittle vacuum bags?

#6

I used some stretchlon on one of my experiments and had a similar problem. Especially around the spiral. Like others said use a different material.

#7

Stretchlon film is super thin and has super stretch, I use to use it as well and had the same problems. Change to thicker film. Check out the airtech homepage. Now I´m using the econolon film, thicker and cheaper. Never had a similar problem again.

#8

I agree.
Strechlon is good for curvy parts but in my experience it tears a bit easier, requires more skill to seal around the edges, and breaks over spiral wrap.

#9

You will always have this issue with that material. If you need to use it then consider double bagging.

#10

Questions:

Which Stretchlon? (they have several)
Which resin? (polyester or epoxy)

Econolon film is 38 micron (0,0015") which is equal to the thinnest Stretchlon (the 200). So Econolon is not thicker at all…

For small parts you could get away with Econolon, however I prefer a sturdier bag, like WL5400 in 50 or better 75 micron, or SL500, or Big Blue 100 (which is 70 micron).

These are all pretty cheap. They also have more expensive stuff, with moisture lock barriers, etc (WL7400, WL8400, KM1300)

#11

I’l be direct here.
The best thing you can do with that stretchlon is find your nearest bin and run to it and dump it. I used it about 3 or 4 times probably close to ten years ago and had the same problem. Had good vac until I started infusion, did’t matter if it was VE or epoxy it just broke down with the chemical.

#12

By the looks of it you are using Stretchlon 200 (green), since my first infusion years ago until now all I have ever used has been Stretchlon 800 (reddish/pink color) and I have had no problems at all. So you might want to use the 800 instead also if you want to make sure you have no tears or holes you can also hold your bagging film above your head to lights in the ceiling to see if any light come through. You might want to find a better storage for you film also, I have a 12 roll fabric rack so all my bagging film and fabrics stay nice and neat, also what was said before pleats help a lot on your resin and vacuum lines.

#13

I use Stretchlon 800 everyday at work and it stands up to some pretty harsh punishment, I’ve had it drug across hanger floors, heated to over 350*, and had some pretty harsh solvents get dumped on it. The green Stretchlon 200 on the other hand seems to crack and break when there becomes a pleat or crease. But the 800, aside from M.E.K and acetone, it’s pretty hardy.

#14

I had nothing but problems using Strechalon 200, the green stuff and infusion. The stuff is fine to use for vacuum bagging with breather material in the bag, however spiral wrap and even the corners of infusion flow mesh (the green stuff)would pop holes in the stuff. I tried to use it a couple times but I would pull a vacuum, wait for a while, and then would see hole after hole pop up so I gave up. That being said, like someone else mentioned, the Strechalon 800 is much thicker and seem to not pop holes all over.

#15

also remember shelf life and handling play a large role in the product performing properly. Also take in mind the temp and humidity of the climate you live at will affect your material and is why its important to make sure to store it in controlled conditions. Good luck getting it figured out.

#16

Thats what I always say, don’t use a stretch bagging film. Use a compound Bagging film made from PE/PA/PE. Than there will be no problems with holes.

#17

sorry for the misinformation on the thickness, but still I never had the same problems like with stretchlon 200. Herman obviously knows better:D

Only double bagging helped with the issue in my case.

#18

With Stretchlon 200 I have seen various results. Indeed the same problem as many of you, but I also have a customer who is using it for polyester infusion, something that is totally not recommended.

On thickness: When things get larger, you really wish for a thicker bag. The thin ones just don’t cope with the abuse.

#19

Wow, thanks everyone! I think Ill just put the 10 yards I purchased in storage and switch to a thicker bag!!

I finished my infusion last night, I just posted another thread. It came out well, but I need a little help :).

#20

http://www.airtechonline.com/whatsnew/index2.htm