Joined: Sep 2010
Location: Tacoma, WA
Project #6: Carbon Fiber Hanguard Deflectors - Part 2
Click here to go to part 1 of this project.
Now it's time for gelcoat. To make the bome brew gelcoat, I use the following products:
- US Composites 635 thin resin with medium hardner
- US Composites red pigment
- West Systems 404 High Density epoxy filler
Of course you'll also need two mixing cups, a stirr stick, and a brush or roller (I chose to use a brush for this mold).
Here is a pic of the materials needed to make the gelcoat.
This is the first time that I have used the West Systems 404 filler. It is much denser than the Cabosil that I have used to thicken the gelcoat in the past. It also requires much more of the filler to thicken the epoxy to the desired consistancy, but from what I read, it adds a lot of strength to the gelcoat layers.
Here is a shot of the 404 vs the Cabosil. Notice how much denser the 404 filler looks compared to the fluffy Cabosil.
Anyhow, you mix up your A B epoxy parts, then mix in filler to taste (the idea is you don't want the gelcoat to slough off the vertical surfaces), and then mix in the whatever pigment you choose. A little pigment goes a LONG way, so add it slowly. I chose to use red because it shows future gelcoat applications in order to gauge consistant application thickness.
Here is the tooling gelcoat mixed up and ready for application.
Then I simply brushed the mixture onto the plugs and flanges and let the whole thing sit under the heat lamps for a couple hours at a time. I applied two coats of gelcoat with about 1.5 to 2 hours between coats.
Let the gelcoat sit under the heat lamps until it feels sticky to the touch, but it won't stick to your finger. At this point it is time to apply the fiberglass.
You want to have all your fiberglass cut before you start. To make this mold, I decided to use 8oz 2x2 twill glass. I think that I cut around two yards of glass total to make the mold. I cut strips, small squares, and a few large pieces. The different sizes of clot allow you to lay up the mold in such a way where you are applying cloth in the direction and location s of the most stress.
Here are the pieces cut.
I also used some scrap glass, as well as some glass tow (yarns) to fill in the corners of the mold.
When all your reinforcement has been cut and is ready at hand, it's time to mix a clean batch of epoxy and start your layup. Go slowly enough to give yourself time to think about where best to place each pice of fabric, and make sure that you use the bristle end of your bursh in a stabbing/tapping action on the wetted glass to remove air bubbles.
Clean epoxy ready to be applied to the tacky gelcoat.
This mold took me about two hours to lay up, but I feel the spent time pays off in the end.
All the glass has been layed. Now we'll wait for 36 hours for the mold to cure under the heat lamps.
36 hours later I pulled the mold. It popped right off. I was really excited to see that all the clay stuck to the mold. This will make for easy clean up.
To clean the majority of the clay off the mold, I simply scraped it off with a plastic body filler spreader. Most of the clay was still clean, so it went right back into the clay bag ready for the next mold.
With most of the clay removed, it was time to trim the mold.
The time had come for me to try out the Fein Multi Master in action trimming the flange of some nice thick fiber glass. I'll have to say that I couldn't be more happy with the performance of this thing, and recommend it to anybody who is doing this type of thing.
I used the Ti saw blade which is made for composites to make the cut. It worked very well.
The Multi Master is a recip tool, so the saw blade doesn't rotate all the way around. This makes the tool very easy to controll, but I think that thing I like most about it is that it doesn't kick dust all over the place. For the most part, all the dust from the cut simply falls onto the work bench. Of course I wore a respirator, but there is no need for glasses or the large face mask that I usually wear. I'm in love I tell you.
This is all the dust from the cut, just sitting there ready to be cleaned up. As I type this, I notice that my arms aren't itchy.
To mark the area I want to trim off, I use masking tape as a guide. It works very well.
After I trimmed all the flanges, I sanded the rough edges with 80, then 220 grit sand paper. This makes the edge nice and smooth.
Here's the trimmed mold.
To finish the mold clean up, I just washed it in the sink with dishwashing soap and warm water.
Here is the cleaned mold, but not quite ready for action.
The deep scratches that you could see in the plugs are evident in the mold. I have never wet sanded any of my molds, but I think that i'll give it a try on this one. After a little bit of wet sanding, it's time to lay up some parts!
Whadoyaknow! I was able to find the time to wetsand and polish the mold today.
I started off with 800 to sand out some of the scratches (now little ridges because this is a mold, thus a direct opposite of the plugs). This makes the scratches a little easier to sand out. I like to keep a little tuperware of water with a little dish soap in the shop for wet sanding. It does the trick nicely.
Here I'm getting my sanding on, once again. If you do this kind of work, you'll quickly find out that there's no end to the sanding.
From 800 grit, I went to 1000, 1500, and 2000 followed by rubbing compound and polish. This is the result... not as shiney as I hoped.
Like I mentioned above, I have never sanded any of my molds before, so I don't know for sure, but I think that the reason that I'm not getting as much shine out of the tooling gelcoat is due to the 404 filler. Just like paint with fleck in it, you can't polish it to a bright luster shine, I think. I think that the little bits of 404 filler in the epoxy just don't shine up much, but the mold is now very smooth and I think that it should do the trick.
Things get better. Once I started to apply the mold release wax the shine started to come back a bit. This is after 4 applications of wax, and it's not as shiney as shiney clear coat, but it's pretty shiney and very smooth.
I also sanded the flanges with 220 grit. The clay left some high spots and burrs that were a little sharp and catchy. These little points could cause a hole in a vacuum bag, and leaks are no fun, so I decided to take action now. I may try to lay up some glass in the mold tomorrow to get an idea of how it's going to work.
I decided to make the first lam with the new mold today. These parts aren't planned to go to Zoomzu, but rather I wanted to play with a couple ideas.
The mold had already been waxed, so all I had to do was apply the PVA as the last step in the mold release application process. Here the mold has had PVA applied.
I wanted to create some sort of graphical design for Mike Z's hand guards, but I wasn't clear how to get there until I read a thread a day or so back where a guy was applying some light glass fabric to the back of his carbon fabric to keep it stable. I decided what the hell, I may as well give it a shot.
What I did was cut some 2oz glass, sprayed a light mist of Super 77 adhesive on it, then layed the carbon, and carbon/kevlar highbrid fabrics onto the glass fabric like so.
This is tricky, but if you take it slow you can get the fiber glass to lay nice and smooth on the other fabrics. That Super 77 is some awesome stuff.
Next I drew a little Z on some card stock, and cut it out. This would be my template. With the template, I traced the Z onto the glass fabric that was glued on the back of my carbon and highbrid fabric.
I use the Fiskers Titanium scissors that you can buy at HD. They work well if you only use one for Kevlar and another for glass and carbon. This is how I keep track of the two.
With my Kevlar scissors, I cut the Z design out of the carbon/kevlar highbrid fabric. It worked well. The fabric didn't appear to want to fray, and the weave was super solid. I had a big smile on my face.
The blue and black Z is flashy, but I wanted to add a little more punch to the graphic.
I had stabilized some carbon fabric as well, so I traced the Z onto it, and cut about 1/4 of an inch outside of the Z all the way around. Then I glued the smaller Z ontop of the larger Z. AWESOME!!!
Now for some mold work.
I had brushed the first coat of epoxy into the mold before I started cutting the Zs out, so now it was time to lay in 1 layer of 8oz glass. The reason for the glass is there will be apparent in a moment. Next I placed both Zs in their respective molds like so.
Following the Zs, I layed the layers of carbon. The final layup looks messy, but keep in mind that this is only a proof of concept and not the final parts, unless they turn out totally awesome. They may turn out totally awesome...
Here the laminant is resting under the heat lamps.
OK, so back to that first layer of glass. The glass is the first layer because I'll probably have to sand these parts a bit to make them look good. When sanding, I don't want to sand into the kevlar/carbon highbrid fabric, hence the glass. Sanding into the glass is no problem at all.
Because these were just a test pieces, I popped them early. No harm though. The resin cures quite quickly under the heat lamps.
Here is the right deflector fresh out of the mold.
I trimmed it up with the Fein MultiMaster which was a dream of a trimming experience even with this green epoxy. The Multi Master trims contours much better than I thought it would. Can you see that flashy Z?
I held the deflector up to my bark buster and it looks like the fit is going to be very nice.
The part was dusty and I still needed to wash the PVA off, so down to the sink we went. Here it is after washing. The Z blends in more than I would have thought, but I'm betting sun light would really bring it out. The tight weave CF also adds a very intersting demension to the CF refraction illusion.
Add a little bit of camera flash or sunlight and it really pops.
So the part is strong. The Z idea is pretty cool I think, and opens the door to a lot of possibilities, but there are a lot of micro bubbles and other imperfections. This all really boils down to laminating technique which is a skill that I am still trying to master. I really want these parts to turn out perfect, so I decided that the time had come to begin to experiment with infusion.
Click here to see how I got started with resin infusion.
After spending a fair bit of time learning how to infuse composite parts, I finally decided to give it a try in the deflector mold.
Here is a quick video of the first test infusion.
After the parts cured for 24 hours under the heat lamps, I pulled the vacuum bag off to expose a very brittle, crips package.
After tugging, pulling, and yanking the peelply and infusion mesh out of the mold, I was finally able to pop the parts out. They turned out perfect. No bubbles or imperfections. This is what resin infusion is all about, folks.
I used 3M Super 77 spray adhesive to hold the dry fabrics in place in the mold, so the mold needing a bit of tending before I did any work on the parts. I gently scrubbed the mold with a scrubby pad and soap and water. No big deal.
After the mold cleaning chores were out of the way, I got to trimming the parts. Here they are fresh out of the mold with the flanges trimmed off. You'll notice a flat finish on the carbon. This is more of that Super 77 spray adhesive. Unfortunantly the spray is necessary to hold the dry fabric in place while the infusion package is put together, so it's kind of a necessary evil. There are spray adhesives that are made just for this pourpose, but I have yet to be able to get ahold of any.
I cleaned the 3M spray adhesive off with acetone and a lot of elbow grease. Then I scuffed the surface of the deflectors in preperation for clear coat. I placed the parts under the heat lamps to warm them up a bit.
Shortly after spraying, Mike (Zoomzu) showed up to lend a hand in making his deflectors. Here he is gearing up for some action.
Mike's KLR has a blue kevlar/carbon highbrid fabric covering his fering, so we wanted to include some of that fabric into his deflectors. We decided on a tear drop shape.
With the first (sandable) layer of fiberglass down, I placed the highbrid accent fabric into the mold.
Next we added the rest of the fabric and infusion material, bagged the whole thing, and pulled the vacuum. Mike made the vacuum bag this time, and the vacuum was perfect. Nice work, Mike!
We mixed up some more of the 2712 infusion resin, degassed it, and infused. I decided not to use infusion mesh on the parts this time so see how the resin would infuse with just peelply over the parts. It seemed to infuse fine, but it took 55 minutes. That's 44 minutes longer than it took with infusion mesh.
Here's a little video of the infusion.
We're getting close to the end of this project, so hang out, relax, grab a beer or a nice hot coffee, and I'll post back soon.
Back at it! No rest for the weary here I tell ya.
I pulled the mold out of the bag this morning. It's an interesting experience pulling the vacuum bag off a mold. In one hand, you are really excited at the prospect of seeing a perfect part come out of the mold. On the other hand, you know that you have a lot of tugging, and yanking of peelply, mesh, and other stuff that doesn't want to come off the mold and the parts. Not to mention, while you have your hands in there trying to grip these things, the little shards, and blades of cured resin are cutting and poking you. It is an interesting experience.
At any rate, I made it through. Again. And I'll have to say that I'm excited, and motivated by what I see. The parts are fantastic.
The above picture is the last one that I'm going to show of Mike's deflectors until I deliver them, but hang tight. I'll post lots of pics of the finishing process, and them mounted.
In the mean time we can mess around with the test deflectors that I made earlier.
Here they are finished and ready for mounting.
Nice solid fiber. No bubbles or blemishes.
I mounted them to be bark busters like so. Those smudges on the inside of the deflector are polish residue.
I wasted no time mounting them up. The following pictures show off the new deflectors.
The new deflectors all mounted up. Look how shiney and pretty they are. I'm sure that they won't stay that way for long though.
I'll have to say that I am very happy with the finished product. Of course this is not the end of this build. First we need to deliver a perfect product to fellow inmate Zoomzu. Once that's done, this project will be finished. No worries though. The next project is going to knock your sox off.
Click here to go to part 3 of this project.
therivermonster screwed with this post 02-16-2013 at 05:45 PM