Finished my first infusion! Need some advise though :)

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#1

I finished my first infusion last night. I kept the vacuum on for 24 hours and the part came out pretty good for a first try. Though the resin melted the cup in my catch pot… I do have some issues though so I was hoping I could post some pictures and get some advise.

The finish is great on the flat areas, but I had real problems around the edges and curves. I believe this might be due to “bridging” and the fabric was not touching the mold.

I also think I need to clean up the edges of the mold where is is rough from the clay while making the mold.

How can I get the fabric to lay on the mold really well? I have heard of people using a spray adhesive? I just wouldn’t want my finish to be compromised because of using something like that.

Any and all advise would be great! Thanks everyone!

#2

This is the part you made from the thread about having all the holes in your film right?

You shouldnt need any adhesive for making a part in that shape. Im guessing that the voids/gaps could very well be caused by all those holes you had and losing vacuum.
If you have the cloth bridging a edge/corner and infuse, you end up with a big solid chunk of resin in there. I think your problem is more of you infused it, then you got holes and lost vacuum and the fabric lifted so you ended up with gaps

I would just try it again and just make sure you press the fabric down into all the edges/corners after vacuuming it down.

#3

Yes, this was made with Stretchlon film and I had a lot of issues with holes in the first 2 hours of the infusion. I keep reading/hearing about bridging but wasn’t sure what would happen. It makes send that these are air voids from when the film lifted up.

Can I use anything or are there tricks to help ensure the fabric is pressed into the corners really well?

#4

-lay fabric
-lay infusion materials (if any)
-lay vacuum film
-pull light vacuum
-adjust bag
-press down fabrics into corners
-pull some more vacuum
-check fabrics for bridging
-adjust when needed
-adjust some more
-use a rounded plastic rod to press down further
-once you are happy, pull a full vacuum
-check once more
-infuse.

#5

Quick question on the “lay infusion materials (if any)” step. I lay fabric, then peel ply, then infusion mesh. Can you actually not use any peel ply or infusion mesh?

#6

Depends on the size of your project, and the permeability of the used materials.

Infusion of small parts in carbon can be done with partially infusion mesh. And using special infusion fabrics (high open space, so take lot of resin) can remove the need for mesh totally.

#7

I completed a second infusion. The good news is that I was able to lay the fabric just about perfect and there is hardly any distortion in the weave.

The bad, as seen in the pics below is that I still have areas that don’t have thick resin. It looks like the fabric was pressed hard up against the mold because its the correct shape, but wherever the fabric bends, the resin is very thin, or not present.

I had a real good vacuum this time ( I think). I used different vacuum film and didn’t have any hole issues. I did a vacuum test before infusing the resin but the bag wouldn’t hold a perfect vacuum when both ends were sealed. But since I was going to leave the vacuum running for 24 hours it didn’t seem like it mattered, as long as the gauge didn’t move.

I had one issues during the infusion that may have caused this. When the resin was starting to cure the cup in the catch pot started melting and made the resin in the catch pot boil up (I will not longer use Solo cups since them melt). When the resin foamed up, it pushed the resin into the vacuum line and I lost vacuum for about 3 minutes. The vacuum film stayed solid, but did loosen some. I quickly pinched off the lines and replaced them, once I turned the vacuum on it pulled back to -30 and ran for another 20 hours.

I believe I had the fabric pressed firm against all of the mold surface, so why is the resin not sticking where ever there is a bend in the fabric?

Since I am leaving the vacuum on during the whole infusion, is it just sucking the resin out?

Do I need to just keep working on my bagging and get a 100% vacuum and then just seal the vacuum end and let the part cure without vacuum? That is how CarbonMods/Easy Composites suggests doing it.

I have not started a third infusion, I wanted to wait and see what kind of response I get from these pictures. Any help would be great! Thank you!

#8

You need to slow down the infusion let it saturate the coposite

#9

The resin flows through the part very fast. How do I slow it down?

#10

Can I slow it down by using no infusion mesh? Or not mesh as just run a spiral down the middle of the part to spread the resin?

#11

looks like your bagging was leaking. You should not loose more then 1inhg in 15 min on a leak check of the project before infusing IMO. Edit with a resin the cures fast.

To slow the resin you can use less flow media and use a resin brake (an area before the vacuum line with only peel ply)

An example of how I do it but I’m no pro…

#12

You need a perfekt vacuum!
Take a look at our MTI video, there you can see how to make an infusion.

#13

I know it can be a PIA to find leaks but you need to make sure the bag is leak free before doing an infusion. ( ^look like DDcompound beat me to it) I use Stechlon 200/800 and would only have a problem with the first yard of material off the roll due to handling. Once I get into the roll I don’t have any more of the micro-holes. (just as a FYI cause I read your strechlon problem)

Once you have the leak free bag you can start the infusion. I assume air got into your bag when you had the resin problem, or maybe threw the leaks? Either way, that combined with a infusion that might have went to fast would have caused this issue. To slow the infusion down you can just use a smaller intake line, or partially clamp the intake line. Other options would be to play with spiral lengths and positions and flow medias. I would start with making sure you have a leak free bag and maybe slowing down the intake.

#14

Thanks guys. I think I am going to try to envelope bag this part as it might be easier than how I am doing it now. Ill also slow the infusion by clamping the line.

-Question: Why do people leave the vacuum running for 24 hours while the part cures if the vacuum is perfect? Watching the CarbonMods video they clamp the vacuum hose off and call it a day.

Thanks!

#15

Thanks again everyone. I am going to try again tomorrow after work and will post up my results.

#16

Oh, one last thing before I try again. It sounds like I need to get a 100% perfect vacuum before infusing, so if I can do that, should I leave the vacuum running during the whole infusion? I was planning on getting a perfect vacuum and then doing the infusion, and then clamping off both ends and leaving the part for 24 hours.

#17

In getting a perfect vacuum I mean doing a leak check and not seeing more then a 1" drop of vacuum over 10min. And NO don’t clamp off your vacuum line when your done with the infusion, leave it on till cure.

#18

I listened to Rotorage and a few others on this board and after a few trial runs on flat panels the parts I did came out really nice. These guys saved me hours and tons of dollars by doing the things they suggested. I did a Porsche roof and a Porsche rear hatch and they have a few problems but are pretty nice. For sure better than vacumn bagging. I learn each time but not in a way that ruins my parts. Lots to read on this board concerning infusion. Just do some searching and reading. Thanks guys!

#19

Make a first bag like you did it. Than put the complete mould in a second bag, you can use the same vacuum pump. When using a double bag you can be sure that it is tight and that no air can travel in the part.
When you take a look at the videos where the vacuum is clamped off you can see a lot of air in the flow media, that means you will normal not be able to get a perfect part (it is possible, but the chance is very small)
If you made a perfect infusion there will be NO air in the flow media.
The best vac test ist to clamp both lines and wait 24 hours.
Before saving money you have to get a stabil process, thats the fastest and cheapest way :slight_smile:

#20

1: leave the pump on until it has cured, only clamp off the resin line when done.
2: resin brakes help. ie: don’t put flow media over the ENTIRE part, just injection side. leave the flow media 1/2-2" shorter than the part before the vent. use a layer of peel ply to make sure air and resin flow
3: slow the flow by clamping the resin line slightly. Carbon takes a long time to wet out compared to glass fabric.
4: even if you have bridging in the corners, you can get air pockets there, not just a solid mass of resin. always depends on if you have any air leaks, and your resin flow speed.