I did one of my backyard garage layups today. I made come plate material. 8 plys of carbon fiber between glass.Added a little silica and chopped fiber to the surface coats, vacuumed to 25hg. The layup looks great except for the usual pinholes throughout the weave.Can anyone give me some tips to get a layup the 1st time that wont have to be re-worked to rid the pin holes?
Thanks
Terry
What Im thinking I have to do is apply a coat of epoxy on each piece of glass, let it go green, do the layup , and then bag it.
Might this help? Or is there a simpler answer?
Im sorry, one more thing. Could the problem be that I vacced the thing down to 25hg and then immediatly lost the vacuum a couple times down to somewhere like 10hg before I got a good seal.Could this cause the pinholes from squeezing and then letting off?
If you lose vacuum, it’s game over.
Im trying another one right now and I am holding vacuum at 26hg.
Ill post how it turns out in a few hours.
Thanks
Same problem on 2nd plate. Only now a few big air pockets along with the pin holes.
I have no idea what where Im going wrong.
Too much vacuum?
No surface coat?
Im hoping to get a few ideas from the pros.
Ive have better results by putting weight on top of the two panes of glass
Thanks
youll get a better surface doing infusion
With vacuumbagging you’ll pull out the resin between the fibers.
So I just do the first layer without a vacuum.
When I do need to use vacuum I use a 25 grams glass layer. You can’t see it, weighs nothing, and is so fine you won’t have pinholes in the surface.
Ive never done infusion . I will give it a try in the near future though. I have a friend that has a stainless steel plate press he lays up plates in without infusion and they come out nice. I just think I am doing something wrong with my procedure. I havent had a chance to talk to him yet.
Thanks for the imput
I am for sure pulling the resin out of the fibers. Your suggestions may be helpful to me but 1st I want to make sure there isnt a way to get a good clean hand layup just using the meathod I am attempting.I have it in my head that it can be done but I am missing a step.
Thanks all for advise
I think I should fill you in more on my set up.I realize it basic but Im sure Im missing something.
I have a large bottom glass plate mounted to malamine.
then a sheet of peel ply
then 8 sheets of 8.3oz. carbon fiber
then another sheet of peel ply
then another glass top mounted to malamine, (no breather)
I bag the layup to the bottom sheet of glass and the vac connection is in the center on top of the malamine with a chunk of breather the connector.
i dont understand your whole setup, maybe a pic would help?
the pinholes are a mystery to me too…im getting close to making vacuum bagged parts almost pinhole free though… surface coat wont help, you can get pinholes (air between the fibers) underneath the surface coat too. i believe its got to do about how resin rich your first layer is…
I apreciate the help.
I just layed up the last plate.
Im thinking In my earlier two layups I have set the top plate on and then lifted and re-adjusted which would give me air bubbles big time. So this time I put on each layer real slow as to not get air in the epoxy. Then I slowly set the top plate in place.
I am using peel ply on both sides . I started by laying out a piece of peel ply, wetted it out and did my layup from there, then put on the top peice of peel ply, worked out every air bubble and then the lid, and vac bag.
Im new to the forum but I will try to get a pic of the setup on here tonight.
This material is mainly for structural I am building some rocket fins with a core material and this material will get cut to be the edging.
I dont want to use compression clamps anymore so it is very important to me to get this process down .
It sounds like you are getting an end result I am looking for so I really , Really apreciate the help.
Thanks, Terry
Heres a pic of the set up
Heres a picture of my 1st layup.
I layed up 1/2 with peel ply and half straight to glass. I got a couple large air bubbles and a ton of pin holes. I may have adjusted the top plate though.
Tomorrow I will post tonights lay up. I went very sparingly on epoxy but I believe it should be enough to wet out everything.
The vacuum is holding good at 28hg.
One other thing I was doing was letting the whole deal sit and hour and then putting it in an oven. Tonight Im just gonna let it air dry.
Thanks again
it looks like you have no way to get the air out of the laminate since your using that top caul plate. either you need to get breather directly on to your laminate or you need to do an infusion to remove the air. at the very least you should have breather around the edge of the plate but I think that still will not be enough to remove the air considering the size. other than that would take a lot more pressure.
High Hojo,
On this layup I do have a 3" wide strip of breather around the inner perimeter of the top caul. On the last 2 layups I did not.
I wonder if it would help to lay a piece of peel ply on the top laminate and then breather across the whole top. and then the top caul.Maybe this is what I am missing?
Ill show a pic of this last layup this evening and if it is less than desireable maybe Ill try covering the whole laminate with breather material.
Ill also give infusion a try in the near future but I for some reason thing a setup close to this can produce what I am looking for . Im wondering if setting my vacuum connection to the side of the layup instead of on top would make the whole deal act more like an infusion type deal.
Thanks for the imput.
This morning Im thinking like hojo saud . This vacuum is not enough pressure.I want as true as possible and light as possible.
Maybe a bunch of cinder blocks will work better?
I have a freaind that has this set up.It is made out of stainless steel and it is heavy. The top plate must wiegh 150 pounds. This is a great setup but it is stainless steel and expensive.
you could try puting the last layer in dry this will help it breath until the excess resin gets pulled in to it. why do you want to use the caul plate? you can get a nice flat panel without it.
Ive made a few plates without a top plate and they do turn out good. My best plates so far are made just by putting a top and bottom caul with 6 cinder blocks on top.
Im just trying to come up with a system that will give me the best strength to weight ratio and trueness that I can get in a back yard set up.These plates will eventually become hi power rocket fins exceding maybe mach 3 or even mach 4.
The picture of the stainless steel press I posted works great but too much $$$. Not to mention the man that owns it has 10 years experience using it. I would like to talk with him but havent been able to reach him yet.