Vacuum infusion ques

General Composites Discussions Composites Talk
#1

Just stumbled on the forum and this is by far the best forum for learning composites i’ve come across. It’s great to read answers from people with a ton of actual shop experience.

I have some experience wet laying fg with per, but still going through the learning curve on production quality work.

I’m trying to make motorcycle fairing peices. I’m starting with tails. This picture isnt the exact piece i’m goin to make but it is very similar in overall complexity and size.

This is a copy of stock bodywork by Sharkskinz, it’s a Suzuki gsxr1000 tail. This peice is about 30 in long 10 in high 18 in wide. Ignore those two holes on top and the entire bottom is cut away starting from that lip you can see underneath in the pic.

I plan on making pieces with silmar 249 surfboard resin and .75 mat glass. I’m getting the clear stuff because I might be working with carbon fiber and hybrid when I get confident later on and the clear epoxies I’ve found are way too much, and the strength isn’t needed for what it’s being used for. Plus I may want to spray the stuff, and using mat is much easier than woven. Finaly cleaning the finished pieces by wetsanding, then prime and paint. If carbon or hybrid is used, then wetsanding and urethane clearcoat.

to get me headed in the right direction does this look like a shape that can be vacuum infused in a two part mold (the seam would run along the side edges, not over the top)? Or would wet lay up be the best route?

#2

sure it can be infused in a multi piece mold

#3

Thats a monumental task at hand…

Id say you start out wiht just making yourself some two part molds and Id probably do some wet layups for a bit.

Infusion is an expensive process to learn, dont let them fool you. Pumps and supplies get expensive, resins get expensive.

#4

Have you made moulds for these tails yet? I made a couple from Sharkskinz and did wet layup. They turned out pretty nice.

#5

That master part looks like it was rotational molded in an expensive alum mold, dry plastic powder placed in the molds, heated in a oven until the plastic is melted, rotated in 2x directions and then still rotating, cooled.

If you never have made a 2 part mold, try something easier first or you might will get bummed and drop out altogether.

#6

Well Im just saying…

pump 3-500 bucks
bagging film, flow media and peelply another hundo for scrap amounts or 400 or better for rolls of it. Then the tape and the pressure pot (resin trap) and the plastic lines and yadda yadda yadda.

Its not time efficient for me yet, I still make mistakes and I still have yet to actually make a bag dead nuts air tight and lose 2 psi within 5 minutes. I have to keep turning my pump on and running it to keep the vacuum at peak. thats going to be costly in itself.

Id seriously just try to keep yourself moving along with easy prodjects like chain gaurds or something till your actually good at it.

#7

I leave my pumps on till it gels. I have been using the same 3 pumps for about 2 years all running about 5 hours a day and don’t have probs with it. I would suggest leaving the pump on not turning them off

#8

Making my plug is as far as I’ve got right now, (been doing a ton of research). I’m trying to figure out what the best way is to go about making nice parts reliably. I was wondering if the seam in this mold would make vip a nightmare. Other than that vip looks like the best route.

I was thinking my general process could be, have the two parts of the mold apart (mold made from orange tooling gel coat, west system epoxy, woven) treated with semi permanent release (frekote nc 55), spray a gel coat (duratec clear gloss), bolt together, let stage b, put in my cloth, super 77 other layers, then set up the vacuum infusion, turn on the pump and test then go. Hopefully pop it out and just wetsand the seam and trim the edges, ready for some paint.

The hard part I see (other than the givin air leaks and learning how the resin flows) is being able to see what I’m doing under the flange in the bottom half, I would need a dentists or peeping tom mirror.

For this complex shape I’ll probably have to experiment with inlet and outlet placing and i might have to use multiple lines to close and open to help direct the resin.

Is everyone using that es100 to spray gel coat? That gun really doesn’t look worth 120 from pics. How hard is it to clean out?

Anyone know of a good supplier in the Boston area?

#9

This would be a part similar to what someone would buy. It’s a couple hundred so I don’t think anything special is done for it.

I’ve done one peice molds before with tight curves. How hard could adding the two peice and vip process learning curves on top of each other be :smiley:

#10

I think youll find that you should probably make the part in seperate halves if you want to infuse and then join them from the back side.

Im telling ya, that type of tail is going to be a nightmare if your going to try to infuse in a multi piece mold. Its hard enough to keep vacuum without a seam running downt the middle of the part.

#11

I have to 100% agree with that.

You could make the 2 piece molds with an extra lip where the 2 parts will get bonded together. It will leave a seam and need after bonded together, post finishing work…but the only real way to do that part.

#12

Im no pro but that is how I did my bike tail.
Made two molds with a line in each mold at the same point where the parts will be put together.
after infusing the 2 sides trim at the line(s) and I tacked it together with CA glue (model airplane glue has a spray to make it set in like 2 sec.) then put masking tape on the seam (outside of the part) run a small line of 5 min epoxy on the inside (to seal the gaps in the CA glue). Then put 2 strips of fabric over the seam on the inside with super 77 and resin that up (epoxy). sanded and cleared.

Pic of the seam one just pieced together and one with a single strand on the seam. I jacked the weave on this one but just to give a idea what the seam looks like.

#13

the single strand over it.

#14

Nice work. Don’t fret the weave as it is like a jigsaw puzzle that is missing pieces, but you know until most of it is together!