im about to do my first part!

General Composites Discussions Composites Talk
#1

just want to make sure i have the process right before i f*^$% it up.

here are my steps

  1. apply wax and pva to mould,
  2. spray in clear gelcoat with duratec higloss addative
  3. allow gel to kick until sticky
  4. wet layup layer of c/f
  5. lay in peel pry, then breather material
  6. seal around flanges of mould and seal bagging film on top
  7. apply vacuum
  8. leave vacuum for how long?

do i sound right so far?

suggestions from the pros?

i would assume that the part should just need a good polishing when i pull it from the mould the next day?

#2

Are you making a part or an over lay as 1 layer of CF will not have the strength…

What resin matrix will you be using as PER rarelys let you vacuum bag beofre it starts to gel which makes vac bagging useless.

#3

Hey Werk…there is a different catalyst for PER that you can use and it will double your work time…cant remember the name of it but its pretty cheap.

I called on it because of doing overlays with it is nearly impossible without it.

BY THE WAY…If you wax your mold right…you dont need the pva

#4

Ah yes, there’s summer and winter MEKP too…summer will slow down the curing rate and the winter is a faster curing rate…:o

See, I can’t remember everything and I glad the rest of you are helping out too! :cool:

#5

It depends on the resin system. If you are using polyester only a couple of hours under vacuum is needed. For Epoxy, well that can vary greatly. Most room temp resins will cure in 12 Hrs. @70F. Benig that this is your first part keep it in the Vac. for 12 hrs. Remember, when that pump is pulling a good vacuum it is not working hard at all. It is essentially free wheeling. We leave our pumps running for 12Hrs. + all the time. Our youngest pump is 4 years old. Our ten year old pump does 12 Hr. stints all of the time.

Also, Werks is right. Add more layers of material if you are making a part. Also make sure that the bleader ply does not touch any wet resin that is not covered by peel or perf ply.

HTH.

#6

what they said! good luck but dont be dissapointed if it doesnt work,just let us know what the problems were and we can help.

#7

I too am new to making composite parts. Please correct me if i’m wrong, but I thought when you lay up a cf part you use epoxy, not resin? Are the two the same thing? If not what is the best type of resin/epoxy ( whichever applies here ) to use and the room temp would be 100 degrees… i live in the desert:eek:

Is “peel ply” used to prevent the resin/epoxy from sticking to the vacuum bag?

#8

resin is just the liquid part of the plastic for FRP.

FRP stands for Fiber Reinforced Plastics.

Epoxy is resin Vinylester is resin and Polyester is resin.

There is no need for expensive epoxies for 99% of the stuff made in the automotive world.

If it doesnt need to have superior structural strength…dont waste the money.

#9

Fast…check this section and the other reinforcement materials section out:

http://www.compositeforum.werksberg.com/showthread.php?t=1345

#10

theres a good question… will generic polyester resin work? even if it cures with a yellowish tinge?

for reference… they are overlay parts… but not a bonded overlay… trim pieces for the interior of a car…

#11

Just a thought…in terms of a generally recognised learning curve, wouldnt it be a good idea to learn how to hand lay a simple part using CSM and poly resin, before going on the far more costly materials and much more advanced production methods?

#12

ClassicBike has a very good point. I bought a plate of glass - a great practice mold! Plus, you can lift it up and see what’s going on underneath to see how you’re adding bubbles, etc. I’ve made a bunch of CF mouse pads while practicing and given them to friends…

Good luck!

#13

thick glass though if you are vacuuming it,i cracked a thin one with vacuum once lol.but being able to see what you have done before releasing it is very handy.

#14

well… ive been mouldmaking for years and doing hand fiberglass layup… im new to the cf parts…

i build about 3 sets of these domes a month


and ive done a few wraps, where i used almost the same process but no vacuum or mould

#15

Ditto with Stew_b on that…we were using dbl panel window frame panel VIP in the classroom until it cracked from the vacuum!:eek:

Then when to 1/4" tempered plate glass. Right REZCAR? :rolleyes:

#16

4SC, nice cf part. I am learning ( obviously lol ) how to lay up fiberglass parts, in fact am doing a rear seat cowl for a sportbike currently. I would consider myself a begginner at best, but it is fun work.

#17

any input on what i asked about using a generic PER? will it discolor the final product? it generally dries with that yellowy tinge… will that be noticeable over the c/f weave?

#18

Make a test panel for you as only you will know for sure in your own eyes.

Does that make any sence?:slight_smile:

#19

sure does… ill try it…

#20

THAT was the metal license plate frame! Not my fault, I swear it!:smiley: