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RE: A few newbie type questions - 12/27/2007 10:17:23 PM   
Ed Smith


 

Posts: 2835
Joined: 12/29/2001
From: Brantford, ON, CANADA
Status: offline 		Jorden,

The parting board must have a smooth, gloss waxable finish. If not the gelcoat will stick to it. The parting board does not have to be as big as shown in your pictures. A 1/2" all round your plug is adequate.

Ed S

(in reply to JKEpps)
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RE: A few newbie type questions - 12/27/2007 11:51:36 PM   
Atlanta 60



Posts: 1076
Joined: 2/15/2003
From: Cartersville, GA, USA
Status: offline 		Here are my little wheelpant molds...I wish I would have drilled them up or at least put some index's on them while I was making the molds...When I was initially doing them I was planning on envelope bagging the parts and didn't "think" I'd ever want to re-join the mold halves...But as it turns out it would make it allot easier for assembling the wheelpants...I'll drill them up someday...But it would have been better to do it while making the molds in the first place... and now I'm wanting to try not bagging the parts and join them wet...So see...We all have to learn some things the hard way...

Try to design the molds to suite *You*...There is no "One Way" to any of this...Listen to other's "experience"...And adapt it to your situation...Then do what makes sense for you...

Have Fun...

Chuck


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< Message edited by navav2002 -- 12/27/2007 11:52:38 PM >

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RE: A few newbie type questions - 12/28/2007 2:15:59 AM   
TeamSeacats



Posts: 161
Joined: 3/9/2007
From: Greenville, SC, USA
Status: offline 		http://www.teamseacats.com/index.php?s=parting+board

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Jake Kohl
http://www.teamseacats.com

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RE: A few newbie type questions - 12/28/2007 1:53:43 PM   
JKEpps



Posts: 605
Joined: 12/10/2004
From: Greenbelt, MD, USA
Status: offline 		Chuck,

That's a great shot of your molds. Now I can understand what Ed was describing in his posts. I didn't realize you could leave the wheel opening open like that. As they say, a picture is worth a thousand words.

Thanks again.

Jorden

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       Post #: 29

RE: A few newbie type questions - 12/28/2007 1:55:40 PM   
JKEpps



Posts: 605
Joined: 12/10/2004
From: Greenbelt, MD, USA
Status: offline
quote:

ORIGINAL: TeamSeacats

http://www.teamseacats.com/index.php?s=parting+board

Jake,

That's a great site you have. I speant a few hours going over what you've done. I had previously found the site for "The Sled" so of course I went back there and spent some time. Talk about a huge effort! I would love to see that thing fly.

-Jorden

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RE: A few newbie type questions - 12/28/2007 2:33:32 PM   
TeamSeacats



Posts: 161
Joined: 3/9/2007
From: Greenville, SC, USA
Status: offline 		Ooooo...thanks for the reminder - my crawler update emails apparently have not been coming through for the sled project...time to post an update!

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RE: A few newbie type questions - 1/4/2008 2:58:20 AM   
JKEpps



Posts: 605
Joined: 12/10/2004
From: Greenbelt, MD, USA
Status: offline 		OK I've finally gotten off the pot, and am now fishin! I was a little hesitant about using my very nice 1/4 scale wheel pant as my first mold candidate. What if the wax doesn't work right, since I'm using regular car Carnuba wax. So I'm using a Sullivan Fuel tank instead. Since I couldn't find any West Systems graphite locally, I used regular hobby graphite. Also, I decided to use West Systems Colloidal Silica (Cabosil). Man that stuff is like fairy dust! Don't even think about sneezing around an opened container! I quickly put on my dust mask to keep from inhaling that stuff. Who knows what it does to your lungs. I tried to pickup some milled fiber too, but couldn't figure out which of the West Systems fillers is milled fiber. So, I mixed up my "toolin resin" using the 105 Resin and 206 hardner. Added 10% graphite and 10% Cabosil, by weight. I layered this on the tank, which has about 6 coats of wax, and two coats (paper towel method) of PVA. By the way, how long do you guys let the Carnuba wax set before buffing and adding another coat? I waited apx 45 mins between coats. Does that seem long? Looking at the working times of the 206 hardner, now I'm wishing I used the 205 fast cure instead for such a small job. It's amazing the few little things I've already learned from just this first attempt. My parting board is thin (1/32) ply that has been waxed and PVA'd. I used some pieces of balsa taped together to create the outline, then transferred it to the ply. I did get a little anxious to get started, so I'm afraid I may not have put on enough layers of wax. I may have just learned another lesson. Anyway now I'm just waiting for the "tooling resin" I mixed to "set up" a while before I start adding my layers of fiberglass. Oh yeah, another lesson, don't wait till or start at 8pm doing this stuff, when you have a 4am wake-up call to get to work. I now know I need to start early, and basically devote an entire day when doing molds and layups. Anyway, enough rambling, here's the pics.



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RE: A few newbie type questions - 1/4/2008 1:38:47 PM   
Ed Smith


 

Posts: 2835
Joined: 12/29/2001
From: Brantford, ON, CANADA
Status: offline 		I am trying to help here.

I have noticed three things that may cause some grief.

The parting board is bare wood but waxed. Being bare wood this might not release as desired. I certainly would advise against this method for the future. I always paint my parting board to get a "Finished" surface.

The release wax used does not specify as "Mold Release" wax. Good luck with that one. You may be misled by that. The gelcoat would probably release from the tank material without any mold release.

In the picture the gelcoat looked as if it was too thick. Gelcoat should be thin enough to be painted on with a decent brush like thick paint. This will ensure proper coverage with no cavities. Spreading it on with a spatula is not a good idea. the outside surface of the gelcoat also needs to be smooth. If not there will be cavities between the gelcoat and the first layer of cloth. The cavities will eventually lead to the deterioration of the mold surface, They will breakout as parts are made.

For your information, Colloidal Silica is a food thickening agent!

I hope the foregoing is helpful.

Ed S

< Message edited by Ed Smith -- 1/4/2008 1:43:46 PM >

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RE: A few newbie type questions - 1/4/2008 5:49:22 PM   
JKEpps



Posts: 605
Joined: 12/10/2004
From: Greenbelt, MD, USA
Status: offline 		Ed,

Thanks as usual, and keep it coming.

Gotcha on the bare wood. It didn't dawn on me to paint it first. Again, another lesson learned. I'm always in favor of using the right tools, just too impatient to wait for an online/mail order, especially since we were just in the holiday season, I know there were delays with places being closed, or delayed shipping. Anyway, I will get some specific Mold Release Wax. I'm leaning towards the Formula Five that you mentioned here. I was using an epoxy brush, not a spatula. It's hard to see the brush bristles in the resin. You are right, it was thick. I wasn't sure how thin the consistency should be, but hey, you gotta play to win right! So hopefully, if this thing releases well enough, I'll whip up another batch and try again. I didn't get a chance to put the cloth down last night. So by the time I get home today, the tooling resin will be fully cured. We'll see how that goes.

Yup I had read that colloidal silica is a thickening agent used in food. I assume that since you can consume it, that doesn't mean you can breathe it without any ill effects. Just the thought of Silica/silicone in the lungs gives me the willies. Maybe an over-reaction on my part, who knows.

Hopefully I'll get more experience over the weekend.

Thanks again Ed

-Jorden

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       Post #: 34

RE: A few newbie type questions - 1/5/2008 2:03:17 AM   
JKEpps



Posts: 605
Joined: 12/10/2004
From: Greenbelt, MD, USA
Status: offline 		Well I couldn't wait to get home from work to check out my mold. By now it had completely cured and was pretty hard. Although, since it's epoxy, I suppose it'll continue curing for the next few days or so. Anyway, with a little negotiation, I was able to pull the tank from the mold, and pull the parting board away with no ill effects. I am very pleased with the results. They werent too shabby if I do say so myself. I do see two small cavities that were obviously bubbles from the resin being too thick. Since this was just a test piece, for experimenting and practicing, I decided not to lay additional layers of cloth to strengthen the mold, since I don't plan on using it. Anyway, enough of the chatter. Take a look, and give me some feedback. By the way, the brown stuff on the back side of the parting board is wax, or more precisely, melted crayon. It sealed up the backside really well, and got pretty had, just like a crayon. Imagine that! I'll probably use melted crayon in the future, as it was easy to work with.



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< Message edited by JKEpps -- 1/5/2008 2:30:54 AM >

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RE: A few newbie type questions - 1/5/2008 2:52:00 AM   
bigben2k


 

Posts: 18
Joined: 10/18/2007
From: Tomball, TX, USA
Status: offline 		Nice work!

The pink stuff... that's the carnuba wax, right?

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RE: A few newbie type questions - 1/5/2008 3:37:01 PM   
RabC


 

Posts: 30
Joined: 12/4/2007
From: BANBRIDGEN/A, IRELAND
Status: offline 		Slightly confused,im a newbee to and was under the impression that the gel coat should be sprayed on,no?

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RE: A few newbie type questions - 1/5/2008 3:55:23 PM   
Ed Smith


 

Posts: 2835
Joined: 12/29/2001
From: Brantford, ON, CANADA
Status: offline
quote:

Slightly confused,im a newbee to and was under the impression that the gel coat should be sprayed on,no?


In an industrial environment spraying is normal. For our purpose brushing is acceptable. I have brushed the gelcoat on all of my molds.

The picture shows a Pylon Racing fuselage mold. The high gloss finish is very desirable. Also refer back to some of Teamseacats boat hull molds/plugs. That is the finish we strive for.

Ed S

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(in reply to RabC)
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RE: A few newbie type questions - 1/6/2008 7:17:30 PM   
RabC