no need. it will just suck up the resin, not change anythign else, like speed, or compaction.
As for your corners. Work ALL the material down in the corners when vacuuming. (peelply, fibers, flow media, bag, etc) Let some air to uncompact it, work it down more, revacuum. Make sure your bagging has enough pleats to have excess material so it doesn’t stretch around corners.
I wouldn’t really use spray adhesive…it might be gluing the layers together, so it doesn’t slide and form tight corners easily!!!
I like it! Peelply on top of the spiral is a good thing, lessens the chance of the bag being cut on the edges of the spiral. Vent line can be shorter. Sometimes I just wrap my tube in peelply, and forgo the spiral, works fine.
yeah, maybe more flow media…but in the end, it infused before it gelled right?
Hi Riff,
Yes it did infuse before it gelled . The good thing about testing with fiberglass is I could actually see if I had any dry spots. This part was well saturated.
I’m really impressed at how you guys stayed with me during this learning process.I wouldnt have had a clue without the help of this forum.
About a year ago you recommended I give infusion a try while we were discussing Tubes. I thought these rocket fins would be a good project to start with.
I still haven’t received the material on order to make these fins. The fact that it taking a long time for them to ship the material ended up being a blessing in diquise. It made me practice.
Hopefully Monday the Carbon will get here.Then Im going to have at it.
Riff , Do you think I would open a big can of worms if I tried to infuse both halves of the molds at once?
Heres a picture of the last test try.
If you shape the core correctly, you can in fuse both sides. if you only have one tool side, the other side will be a rough woven finish, but that can be sanded, or put a layer of uni/fine woven glass/veil on top to minimize that. Might infuse oddly, but it SHOULD work.
The main thing to worry about if you don’t use flow media on both sides, is how well the tool side will infuse…
This is a two piece mold.Two separate halves. Once I make each halve I will glue them together and then fill them with expanding foam.
So I was wondering if I would get myself in trouble if I set up both molds and put a T in the vacuum line and another T in the resin line and infused two molds at once.
I have two make 8 different halves total. So if I could do two at a time it would save me a few days.
I just don’t know if there are issues like vacuum flow or resin flow doing this.
Thanks ,
Terry
There is no problem doing this. I do this regularly on my test table, with usually 8 seperate and different laminates. (and the reason I do not do more, is because the table is not larger…)
Make sure you can clamp the resin lines seperately, in this case. (should be not too difficult)
nay Tbone, that would be fine. Just be extra careful about air leaks. Also infuse both at once…don’t do one, and then do the other…sometimes a drop in pressure causes air voids to form, and then get stuck in the part for the part that is already infused. nothing major…
Sounds good. I’m gonna go ahead and try 2 at once.Of course I have another question. “What a pain in the Butt I am”.
The resin inlet line. Do I just run one line into the bucket and T it off to the other mold? Or should I run two separate lines into the bucket? Or can it be either way?
By the way , Im pretty sure I know why the last infusion went so slow. I did spray adhesive down the carbon. And in doing this I was kinda sloppy and sprayed overspray on the mold flange surface. Im sure that was pinching off the bag.
I’m going to take your advise and not use it, or at least use very little.
Terry
I would infuse with a T split since it means you only need to worry about one inlet line. I’ve done it many times and it worked well. The problem I had with infusing with two lines is that while I watch one the other pops up above the resin line and got air bubbles. However I didn’t strap my lines in or use a funket so it was more of an error on my equipment and setup than it was on the two line idea itself
Just for something more visual I did a basic sketch of how I hook up two molds for one infusion, it’s exactly as described above.
That helps, That just how I set it up. Thanks.
Terry
I tried the real deal today. Everything was going great. Solid resin was flowing . Then I saw a small air leak . As I fumbled around with the leak I looked up and the resin line started backing up again.The whole thing wetted out but it only used 25% of the resin it normally uses so Im sure its not well saturated.And a ton of air was introduced into the layup.
I have no idea what went wrong . It was perfect until almost half way into the infusion.Then I just stood there and watched the resin back up.
Im going to go back to one at a time for now.
I thought for sure I had it this time.
Heres a couple more pics.
Thanks
Terry
are you doing a leak down test before doing your infusion?
Ive been vaccing it down, and chasing all leaks down with a leak detector. Once I have the gauge reading 29". I leave it sit for about a half hour and then go for it.
This time when the infusion started there where no leak but about a quarter of the way through I saw some little air bublles. A very small leak. I think everything would have been fine if I would have left it alone. When I started messing with it I lost the resin fill. But the gauge was still at 29.
Hojo,
Is this what happens if you get a small leak. You will lose the resin feed.
If this is true then that’s what happened. The leak was around that block fitting that I shove the resin line into. Maybe I should try it without that fitting.
Terry
you need to do a leak down test. ultrasonic testers will not pick up all leaks. you must cut the vac source for atleast 10 minutes, and look for a drop in vac. if there is a drop then keeping looking for leaks, otherwise you will more than likely get air in the part.
Once the resin line reaches the leak it will slow down or stop tremendously. This because the pressure differential drops to zero i.e. the vac pump is now “pulling” the air instead of the resin
This I have not been doing. But I will on the next try. I can see now that you cant have even the smallest leak or your screwed.
Thanks Hojo
keep up with it man, watching this thread closely
Ok,Today I gave it another try. I cancelled all the sloppy whistles and bells and tried my best to do a clean setup.
I added a sacrificial ball valve at the resin bucket. And I took Hojo’s advise and did a leak test. It held for 20 minutes so I mixed up some epoxy. Then I spent thirty minutes trying to degas it. I was able to get rid of the air in about 3/4 of the epoxy. There was a foam on the top though.
Here’s some pics of the setup.