Other Wet layup composites, is carbon even worth it?

[harris414]

with some mastic tape and bagging film... anythings easy to pull a vac on
Im a noob to composites but so far this hasn't been difficult with a little thought process and plan of attack!
Its actually been fun, I walk around the shop thinking of things to make lol
Im working on doing some carbon outdoor furniture

 

[Billybo455]

what ever carbon is in the superfreaks is pretty nuts. when we put superwetbretts hull together i had a piece of left over exhaust tube. it was just two layers of carbon i think. none of my friends could break it by hitting it on stuff. one of my friends tried to repeatedly on my nitrous tanks to no avail! don't listen to the people that say you cant do it and get the savings with a wet lay up. just don't soak it and you'll be fine.

 

[XJCrawler]

Love it. I didn't say a word about composites and even still people are trying to twist things around and put words in my mouth. Would love for you to find where I said that...

http://www.x-h2o.com/threads/92769

What is that you actually do? You always claim that your a structural guy, but that usually has nothing to do with composites

 

[McDog]

Your post talks about carbon kevlar and your link is to a carbon titanium discussion?

 

[Cannibal]

Alright...hold on. Lets not turn this into any type of pissing match. We all know that theoretical and practical applications can very greatly, and we also know that what is perceived as the proper practical application can be done better with proper technique. No one can argue that the common "forum wisdom" can be miles apart of industrial application and theoretical teachings.

This is good feedback so far. I will have to look into the vacuum bagging. Can I use my Food Saver....lol.

Besides trial and error (like harris414's ride plate), is there any way to figure out how much product to use?

 

[chriselmore_1]

What is a cheap vacuum setup to buy? Just to makethe occasional ride plate, or chin pad.

 

[Freakrider]

Just master your tricks on someone else's ski and then forget about reinforcements. :clown:

 

[WaveDemon]

Besides trial and error (like harris414's ride plate), is there any way to figure out how much product to use?

take a sample from a builder hull (scupper tube hole, handle pole vent holes, bilge hole) and burn it with a torch. That will removed the resin and show you the weight and number of layers.

 

[Cannibal]

What is a cheap vacuum setup to buy? Just to makethe occasional ride plate, or chin pad.

I've been reading about them, short of a used vacuum pump from Craigslist or something, the cheapest is either a Harbor Freight Vacuum pump at $120, or if you are creative, some people are building ones with fridge or freezer compressors and one of those portable air tanks. Need to rig up a vacuum switch and such, but nothing that looks too crazy.

take a sample from a builder hull (scupper tube hole, handle pole vent holes, bilge hole) and burn it with a torch. That will removed the resin and show you the weight and number of layers.

Interesting method....now who wants to light their freak on fire for me.....

I do have a Blowsion CF ride plate, that thing is thick. I could try this on a corner and see what it looks like. No tray needs to be built that tough.

 

[harris414]

I purchased a gast model# DOA-P704-AA on ebay for 150 bucks, after looking at all the cheap kits and systems that create vacuum using a compressor I found
anything worth buying was going to cost 120+... So after finding a gast for 150 it was an easy purchase, they are like 589.00 new

Depending on what your making, you can get creative and find ways to apply pressure as the part cures and if you wet the carbon properly each layer and apply on area
and squeege air out you will be amazed how it comes out...

I plan on doing hood and pole and more maybe so the cost of vacuum bagging wasn't an issue...

Not sure if i would go burning up carbon parts, depending on the weave type that could be a not so accurate way to find out, and if a quality epoxy was used your going to have to torch it!

Do as I did and play with it, or maybe some more people like me will chime in and give feedback...

 

[WaveDemon]

I've been reading about them, short of a used vacuum pump from Craigslist or something, the cheapest is either a Harbor Freight Vacuum pump at $120, or if you are creative, some people are building ones with fridge or freezer compressors and one of those portable air tanks. Need to rig up a vacuum switch and such, but nothing that looks too crazy.



Interesting method....now who wants to light their freak on fire for me.....

I do have a Blowsion CF ride plate, that thing is thick. I could try this on a corner and see what it looks like. No tray needs to be built that tough.

I've posted the results of this for a wamiltons "carbon" hull before. I have a sample of the scupper cut out. it looks like 4 layers of 12oz biax and 1 layer of carbon, maybe 12-17 oz.

 

[kevbo]

I've been reading about them, short of a used vacuum pump from Craigslist or something, the cheapest is either a Harbor Freight Vacuum pump at $120, or if you are creative, some people are building ones with fridge or freezer compressors and one of those portable air tanks. Need to rig up a vacuum switch and such, but nothing that looks too crazy.



Interesting method....now who wants to light their freak on fire for me.....

I do have a Blowsion CF ride plate, that thing is thick. I could try this on a corner and see what it looks like. No tray needs to be built that tough.

For composite bagging get a small Thomas or Gast diaphragm compressor. They are quiet, use little energy, and can usually pull 26"

 

[Cannibal]

Ya, I'll just take a fine file to the edge and examine it. This ride plate would be plenty for a pole area, way overkill for a tray.

 

[Cannibal]

I've posted the results of this for a wamiltons "carbon" hull before. I have a sample of the scupper cut out. it looks like 4 layers of 12oz biax and 1 layer of carbon, maybe 12-17 oz.

Wow, sounds like a lot of the other "carbon" parts out for the automotive industry....95% glass, 5% carbon.

For composite bagging get a small Thomas or Gast diaphragm compressor. They are quiet, use little energy, and can usually pull 26"

I'll check out ebay. There are some big ones here on CL, but way overkill.

 

[harris414]

Here is a peice i did using 8 layers of the carbon i have sandwiched between glass and a little weight
8 layers (4.8mm thick) is what i did using my ride plate, the ride plate came out perfect using 8, b/c of the curves it added alot more rigity to the part...
this 8 layer plate is real strong but will flex some, Im will be doing my tray in 8 layers on bottom and high strength needed areas. Might add 2 layers more at most in key spots
4 layers will be what i use for the hood and other basic areas...

 

[WFO Speedracer]

Wow, sounds like a lot of the other "carbon" parts out for the automotive industry....95% glass, 5% carbon.



I'll check out ebay. There are some big ones here on CL, but way overkill.

I bought a Skylar rotary vane industrial vacuum pump off of Ebay, I believe I paid around $85.00 shipped, there are deals on there if you can wait and know what to look for, I won't be bagging any hulls anytime soon so for small parts like ride plates up to maybe a hood it works great.The supplies for vacuum bagging are fairly cheap but you will go through a lot of materials in a short amount of time.

 

[WFO Speedracer]

The following was lifted from Carbon Blaster's thread, I thought it fit in pretty well here.

In a nutshell: a 200gsm plain weave carbon & a 200gsm plain weave fibreglass both weigh 200gsm, but the fibreglass is many times more flexable than the carbon, so you would need multiple layers of fibreglass to have a similar rigidity as carbon.
These multiple layers make the fibreglass weigh more.
Hand laying or "wet layup" gives a very bad fabric to resin ratio, making it prone to cracking under stress conditions.
The excess resin is like a piece of glass that when you flex it too much it cracks or shatters.
Vacuum bagging (pre-preg or resin infusion) creates an environment that gives a dramatically better fabric to resin ratio, which is far less prone to cracking when put under stress.
The type of resin you use is very important, the main 3 types are:
Polyester Resin
Vinylester Resin
Epoxy Resin
Polyester is a budget resin designed for making a low stress product from a mould.
Vinylester is designed for high quality products made from a mould & for some repairs. This resin has good impact resistance.
Epoxy is designed for high quality products made from a mould, repairs & bonding. Some epoxies have high impact resistance. The main advantage is that epoxy is also a glue & besides wetting out the fabric it also bonds or glues the layers of fabrics together.
Epoxy reduces de-lamination, where other resins are prone to de-lamination under severe stress conditions, even though they have high impact resistance.
All types of resins are available in different levels of quality, just because something is made out of epoxy, doesn't mean that particular epoxy has high qualities.
Some epoxies can have up to 3 times the tensile strength as the other (especially if you have your resin made for your application), this means you can have less layers of carbon, but still have the same strength as a product made with a lower strength epoxy that has to use twice the amount of layers.
This obviously gives you a very strong, light product.
The disadvantage with these high grade epoxies is they are many times more expensive, need to be used under vacuum & need to be baked in the mould to acheive it's full potential.

Some of these epoxy resins are widely available, an example would be West System Pro set epoxy , it does not require post curing but when you are spending this much cheese curing in an oven or as the composite guys call it an autoclave is the only way to achieve maximum strength.More info on Pro set epoxies and pricing in the links below.

http://www.prosetepoxy.com/laminating_epoxies.html



http://www.aircraftspruce.com/catalog/cmpages/westSysEpoxy3.php

 

[Waternut]

What is a cheap vacuum setup to buy? Just to makethe occasional ride plate, or chin pad.

I'm making my hull with a venturi pump from harbor freight to use with my air compressor. It's loud as anything but it is capable of pulling a deep vacuum. It doesn't have a lot of power though so you have to pull the majority of the air out with a shop vac before putting the venturi pump on. The other difference is, it can't overcome leaks like a real vacuum pump can. So if you have a couple pin hole leaks, it's going to hurt you by reducing your overall vacuum. But...for little parts here and there, it's a very cheap way to accomplish the same goals provided you already have a good air compressor. You also don't need the fancy $50-$60 vacuum ports like the pros use. They make decent suction cups for vacuum bagging for the DIYer. They work well and do seal but they require a little more attention and care.

 

[Breese08SJ]

[FONT=Verdana, Arial, Helvetica, sans-serif]This was taken from a site for vacuum pressing and woodworking ...... As waternut mentioned they are not very efficient and you better have a decent compressor to nurse it along.
Every thing I have read basically says a garbage rotary or diaphragm pump is hands down better than a venturi.



A4: [FONT=Verdana, Arial, Helvetica, sans-serif]Harbor Freight has a venturi pump rated at 28.3" of mercury and 4.2 CFM for only $17. Could this be used for a vacuum press?[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif] [/FONT][/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]I have tried that same venturi with a vacuum press for several years before I realized how inefficient it was. In May of 2005, I sent one out for lab testing and the results were surprisingly disappointing.[/FONT]

• [FONT=Verdana, Arial, Helvetica, sans-serif]First, HF rates it at 4.2 CFM. This the air consumption, not the vacuum flow. What's important is that the true air consumption was almost 8 CFM. In fact, I sent them two more units for testing because I thought the first venturi I sent had to be defective. It wasn't. They all gulped up 8 CFM of air to pull full vacuum.
  

• [FONT=Verdana, Arial, Helvetica, sans-serif]Second, they only pulled between 1.75 and 2.05 CFM of vacuum flow. That's a loss co-efficient of 75 percent.
  [/FONT]
• [FONT=Verdana, Arial, Helvetica, sans-serif]Lastly, there is absolutely no way to muffle the horrendous sound that these emit without further reducing its capability.[/FONT]

[FONT=Verdana, Arial, Helvetica, sans-serif]
[/FONT]I personally use a Welch Duoseal 2 stage rotary Sci- Laboratory pump
http://www.amazon.com/Welch-DuoSeal-High-Vacuum-Pumps-Model/dp/B0017Y8Q2M [/FONT]

 

[Cannibal]

There are some Thomas 2660 pumps on ebay now for 45-65shipped, about 4.6cfm and 26-27." depending on model.

Would one of these work?

John, I got your PM, I might call you and pick your brain about how you came up with the thickness in different areas on your feral hull. The tray isn't the only thing I need to build, it was just my example. I've thinned my SXR hull in front and between the motor mounts for my rocker chop from .58" down to .08 so far and it will get even thinner before I build it back up, it's essentially a mold I'm building up into a part. I want to add as little weight as possible (the bottom deck alone on the SXR was 74lbs), but need the most strength a limited budget can buy. I was planning a few layers of 1208, but if I get some carbon on the cheap, I might go all carbon, or maybe a single layer of 1208 followed by like 3 layers of carbon at 30* angles.