Fun With Carbon Fiber

[SkunkWizard]

I just bumped into this thread. I dabble in composites in my garage every day.
About 90 % of the C/F stuff I do gets painted. I did make a few parts for my DR but my specialty is race cars

I wanted a low fender for the DR so I modified an old Bultaco Pursang fender, made molds and did it with a few plies of C/F and Kevlar



also made case guards with 15 plies Kevlar and 1 ply 8 harness on the outside




I designed, built the mold and C/F VARTM this tail over the summer



I recomend the next can of wax you buy for what you are doing Meguiars #8 mold release
I have many Vacuum pumps, a good starter for the money is one from Harbor Freight http://www.harborfreight.com/catalog...esult?q=vacuum it's .
ebay is a source also
also a good source for supplies http://www.aircraftspruce.com/menus/cm/index.html
I buy all my Epoxy resin from PTM&W (after searching the best resin systems for many years)
I've been doing race cars for 12 years after leaving the airlines as a composite tech for 25 years
I made spare parts and repaired this car since new untill retirement. went with the team for years including the 24 LeMans

[therivermonster]

Originally Posted by ebrabaek

http://www.ebay.com/itm/Vacuum-Chamb...item20cc241934

Is that the complete kit that you bought? Same vacuum pump and all?

[therivermonster]

Originally Posted by SkunkWizard

I just bumped into this thread. I dabble in composites in my garage every day.
About 90 % of the C/F stuff I do gets painted. I did make a few parts for my DR but my specialty is race cars

I wanted a low fender for the DR so I modified an old Bultaco Pursang fender, made molds and did it with a few plies of C/F and Kevlar



also made case guards with 15 plies Kevlar and 1 ply 8 harness on the outside




I designed, built the mold and C/F VARTM this tail over the summer



I recomend the next can of wax you buy for what you are doing Meguiars #8 mold release
I have many Vacuum pumps, a good starter for the money is one from Harbor Freight http://www.harborfreight.com/catalog...esult?q=vacuum it's .
ebay is a source also
also a good source for supplies http://www.aircraftspruce.com/menus/cm/index.html
I buy all my Epoxy resin from PTM&W (after searching the best resin systems for many years)
I've been doing race cars for 12 years after leaving the airlines as a composite tech for 25 years
I made spare parts and repaired this car since new untill retirement. went with the team for years including the 24 LeMans

Skunk, that is some awesome work! I laughed when I saw your blue and CF DR fairing. As you may have seen in one of my previous posts, I'm a big fan of blue painted and CF parts. I love it!!

The race car composite work is crazy! The pic that you posted of your resin infusion (I'm guessing) part is nuts! How long does it take you to lay up, bag, and infuse a part like that? It looks pretty complicated...

Anyhow, thanks for posting, man! I love it when others post their composites projects on the thread. If you have more pictures please post them.

[therivermonster]

I pulled the mold this morning and it does have quite a few pin holes due to bubbles. Any suggestions on how best to fill these and finish the mold?

Thanks everyone!! Here's to all of you!

[ebrabaek]

Originally Posted by therivermonster

I pulled the mold this morning and it does have quite a few pin holes due to bubbles. Any suggestions on how best to fill these and finish the mold?

Thanks everyone!! Here's to all of you!

I am going to tell you something you don't want to hear...... It is not worth the time, as you will be sanding, and filling, and buffeting yourself to death. Hands down.....it is faster to make another one. That said....Before you make another one.... A few things to consider..... After the release agent has dried..... Mix a little batch of epoxy to coat the plug once......
Mix it above 80 deg, but below 90..... after mixing.... set it under a heat lamp....elevate it to 105 deg...... watch all the bubbles pop....Well ....most of them. You are stressing the resin, but on a small piece like this.....not an issue. Or.... heat the plug to 120 deg.....under a heat lamp, and watch the bubbles pop, as you lay down the first layer..... Get the last remaining bubbles with the acetone squirt. Apply two layers this way. It is important that you undestand that you are playing with fires..... But it can work in your benefit.

[therivermonster]

Originally Posted by ebrabaek

I am going to tell you something you don't want to hear...... It is not worth the time, as you will be sanding, and filling, and buffeting yourself to death. Hands down.....it is faster to make another one. That said....Before you make another one.... A few things to consider..... After the release agent has dried..... Mix a little batch of epoxy to coat the plug once......
Mix it above 80 deg, but below 90..... after mixing.... set it under a heat lamp....elevate it to 105 deg...... watch all the bubbles pop....Well ....most of them. You are stressing the resin, but on a small piece like this.....not an issue. Or.... heat the plug to 120 deg.....under a heat lamp, and watch the bubbles pop, as you lay down the first layer..... Get the last remaining bubbles with the acetone squirt. Apply two layers this way. It is important that you undestand that you are playing with fires..... But it can work in your benefit.

Shopping list:

-heat lamp
-new chemical resistant spray bottle (my other one broke)

Another issue...

When applying the first (finish) layers of epoxy on either a plug to make a mold, or in a female mold to make a part, how does one keep the epoxy from sagging, or slipping into the low areas?

[ebrabaek]

Originally Posted by therivermonster

Shopping list:

-heat lamp
-new chemical resistant spray bottle (my other one broke)

Another issue...

When applying the first (finish) layers of epoxy on either a plug to make a mold, or in a female mold to make a part, how does one keep the epoxy from sagging, or slipping into the low areas?

You can't......

[ebrabaek]

There are a few things you can do to minimize it though..... When you lay down the first layer of cloth.... Start at the pooling area, and as you massage the fabric outward.... you move it away from the pooling area.

[therivermonster]

Originally Posted by ebrabaek

You can't......

I love it!!

Originally Posted by ebrabaek

There are a few things you can do to minimize it though..... When you lay down the first layer of cloth.... Start at the pooling area, and as you massage the fabric outward.... you move it away from the pooling area.

That's a good idea. It would probably work to distribute the resin more evenly over a female mold, but not so much with a plug I'm thinking. I guess that the sloughing resin really isn't much of a problem with the plug because it would just drip off.

[ebrabaek]

Originally Posted by therivermonster

I love it!!



That's a good idea. It would probably work to distribute the resin more evenly over a female mold, but not so much with a plug I'm thinking. I guess that the sloughing resin really isn't much of a problem with the plug because it would just drip off.

Correct...... But as you get better at this, you will find that as you message the fabric.... your pushing the resin through the fabric....each layer at a time, and most surplus will now end up on top of the fabric in the pooling area, where you can simply wipe it off......

[zoomzu]

Originally Posted by therivermonster

I like the sconce idea. It would make for a great office, shop, or man cave light.

I might just give that a shot.

You should cut out a hole where the head light goes. Put a light in it .. sconce

[therivermonster]

Originally Posted by zoomzu

You should cut out a hole where the head light goes. Put a light in it .. sconce

I did put a "hole" in it.

(hit it with a hammer to see how strong it was... Not that strong.)

[therivermonster]

I popped the mold off the plug. It was a bit harder this time than any of the other times, but it still came off just fine.
Here it is. Fresh off the mold. I was surprised that the clay stuck to it as much as it did, but the clay did its job.


Out came the Dremel and I made quick work of triming up the mold.


After trimming and sanding the edges, I washed the mold in warm water and dish soap. The clay came off without too much hassell, but a little was left behind. You'll see where soon...
The outside of the mold. It is very rigid.


The inside of the mold turned out mostly nice....


Besides these little guys... There are a number of little holes in the molds surface due to bubbles that were left between the surface of the plug and the first layer of resin. The red clay helps them stand out quite well.

You'll notice the parts of the mold that stand out where I filled the screw and vent holes with clay. These protrusions will print into the CF part and show exactly where to drill holes and cut vent slots.


Earling responded to my message about filling these pin holes and repairing the mold. He said just scrap it and make a new one which is probably the better idea, but I can't help to think that someday I'll have to repair a very important mold that has pin holes in it. So, (sorry earling) I'm gonna repair this mold...
I received an order today from US Composites that included some Cabosil epoxy filler. I think that I'll mix up some thickend epoxy to make sort of a putty, then just rub the mixture into the holes. Finally I'll sand with 800, 1500, followed by buffing and polishing.

The mold won't be perfect, but it should yeild a CF part that is nearly finished, minus a bit of sanding which I would probably do anyway.

We'll see how it goes...

[zoomzu]

Originally Posted by therivermonster

I did put a "hole" in it.

(hit it with a hammer to see how strong it was... Not that strong.)

Oh yeah, now put a light in it and hang it.

[100mpg]

Originally Posted by therivermonster

I did put a "hole" in it.

(hit it with a hammer to see how strong it was... Not that strong.)

ouch...pics or it didn't happen!