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[thegarehanman]

Ok, so I'm planning on doing a tutorial on how to make a fiberglass molded case. Piece of cake, right? Well I've stumbled upon an element that proves to be a bit of a tease. I can't find any type of aluminum(or any other metal for that matter) channel simular to the kind used on the lip of skb and other hardshell cases. This is actually a pretty important factor as far as I'm concerned. So if anyone happens upon something simular to this channel or where it is sold, I'd be greatly appreciative.

peace,

russ

[marksound]

Try some of these sources: Aluminum Extrusion.

[thegarehanman]

You know, I would promise you my first born child, but I've already promised Rich that, so you get number two. I didn't think that H channel could be extruded, but I suppose I learn something new everyday. My thanks to you.

peace,

russ

[Maiden69]

So are you maing the mold inside or out? There are 2 complete different approaches to fiberglass, and making one from the outside is the one that yields the best results. Very easy! If you need any pointers let me know I got quite a lot of experince with fiberglass in the car stereo side.

[thegarehanman]

I actually did a bit of fiberglassing on a sports car I owned a few years ago. I will most likely make the foam insert, wrap it in tin foil, and lay the glass over that. That will allow me to seperate the two pieces so the shell can get a finish and hardware and the insert can be lined. I'm trying to make this very reproducable for all of the hobbyists on this site. Although, I really like the smooth finish that is yielded by using a mold on the outside. So I may just go that route despite the added effort. If you could give me tips on making the "outside" mold based off of the foam insert, I'd appreciate that.

[thegarehanman]

Ok maiden, after some googling, I found a female mold technique that looks like it could be done by an average joe. That's really important to me for tutorials. I don't like to get anything too specialized because I know other people aren't going to buy that stuff for one project. Anyhow, I saw on one site that they made a mold using plaster of paris. Is this feasable? They just popped a plaster mold(I imagine they reinforced it with metalmesh or something simular), sprayed it with PVA(I believe that's what it was called), applied a gel coat(is this equivilant to using automotive clear coat, like putting a finish on it before you put the actual fiberglass in?), covered the inside of the mold with resin, layed a layer of glass down, put more resin down, then more glass. I think they ended up with 3 layers of 3/4 ounce matt, but that was on a 12' boat, so I could probably get away with less layers and/or lighter matt. It said that since the fiberglass shrinks as its drying, you just leave it in the mold til it's totally cured and then pop it out. Sound like a plan?

peace,

russ

[jnewman]

You might also try penn fabrication (www.penn-elcom.com). They specifically manufacture aluminum extrusions for flight case hardware and rack cases and so on.

[thegarehanman]

I'll take a look into it. I've been having good luck finding the right shapes of extrusions for what I need, but normally the h-extrusions have an inside width of at least 1/4." I need something more along the lines of 1/8."

EDIT: Excellent call jnewman, they have the exact thing I was looking for.

If making the female molds is as easy as most tutorials make it look, I should be able to make a pretty kick @$$ hardshell fitted case with (fingers crossed) a gloss finish.

Edited December 15, 2005 by thegarehanman

[Maiden69]

Anyhow, I saw on one site that they made a mold using plaster of paris. Is this feasable?

Plaster is most common for small molds, since it breaks very easy. On to a Guitar case I would use expandable foam. It comes in spray cans but if you can get the 2 part one it is much better.

gel coat(is this equivilant to using automotive clear coat, like putting a finish on it before you put the actual fiberglass in?),

Very close to a clear coat. Gel Coat is just resin with no fiber, is colored to what ever color you desire, and I found is a bit more durable than regular resin, but the color fades like Crazy on the sun.

It said that since the fiberglass shrinks as its drying, you just leave it in the mold til it's totally cured and then pop it out. Sound like a plan?

From my experience I have never had a fiberglass piece shrink on me...

Now here is what I "would" do.

1. Make a mock up case from say 1/4" plywood a bit oversized.

2. get some big trash bags and line the inside of the case.

3. Mix and pour the foam, (you can either leave it uncovered and cut it with a hacksaw blade later, or you can wait until it starts to go above the edge and coverit with a piece of plywood and some heavy weight on top. THis will ensure that the foam gets into every corner evenly)

3. pop the foam out of the "case", Shape as desired. Use a hacksaw to cut the big parts then a 60 grit sandpaper will do for the fine shaping.

4. This step is a bit tricky if you don't have a gun. We used a polyesterfiber primer, it is just a primer that sprays thick as hell, and builds up in a second... You can use fiberglass resin but it is a lot harder to work with.

5. Once the primer has dried we took care of all the imperfections with bondo. Also if you want to add a custom design you can do it now, either with bondo or artist grade playdoh.

6. here comes the fun part, this you have to do outside!!! If you have access to latex (and I don't mean paint) use it, we didn't so we bought quite a few 16oz tubes of clear silicone. I used WD40 as the releasing agent, sprayed the whole case on the outside with it and then using a piece of no lint clothe take the excess out, make sure you get WD40 (or whatever releasing agent you decide to use)! Now start covering the whole thing with silicone (once more! If you can get the latex it is much better since it is more liquid than the silicone but once dried they have almost the same properties) {in the case of this being a case I would make another "case" were this mold would just barely fit, and fill the whole thing with silicone)

7. once this has dried, and in our "small" projects it took almost a week, all you have to do is turn it around and slowly peel the mold out. Once this is done, all you need is gel coat the think, set up a "bath" with resin, then get the fiberglass wet on the bath and start laying out onto the gel coat, if you want a strong case use the chopped variety, the woven one is a bit too flexible.

Hope this is kinda understandable, I'm thinking all the term in spanish and some things don't translate to nothing...

If you have more question or need more clarification let me know and I will post here again..

[thegarehanman]

So from what you're saying, I take it that the original foam insert is just used to make the mold, then you'd make a propper sized insert to fit in the fiberglass case, since the inside of the case would be smaller than the foam insert you made it off.

What I'm thinking of doing is as follows(based on all of the tutorials I've been reading).

1: figure out the exact exterior dimensions of the case

2: make a full size model of the case out of plywood(top and bottom seperate

3: fill the sides of the plywood with bondo,prime it, clear it, and buff it out to a nice shine

4: make the mold of that using mold grade gelcoat, fiberglass, and some creative plywood bracing

5: wax the interior, lay down the gelcoat, and then lay the fiberglass

Seems to be about the same amount of effort as what you suggested. It's just a different approach. Your way sounds less expensive though, I must say.

Edited December 15, 2005 by thegarehanman

[Maiden69]

Yes about the same, different approach and using the "right" compounds... On my case what I do is radical shapes, not a simple square box. If I was to do this it will be on a guitar shaped case or a 3D "coffin" style case. For a square case I think that I rather go the traditional way other than to make a mold for mass production.

I was going to point you in the direction of FishMan Audio in Fl, but the site has been redone and there is not inprogress pics, atleast not id'ed. He is using a fleece fabric that he staples to a frame made from wood and then soaks it with fiberglass resin, once this is done and dried, he just re-enforce from the inside, and use the polyesterfiber primer to smooth everything on the outside. He is a true master on fiberglass car audio work...

[Sambo]

Here ya go...

http://www.ecscase.com/

Should be what you're looking for.

Edit:

Plus this link too

http://www.crtvworks.com/ccase/HARDWARE/extrusions.htm

[thegarehanman]

I contacted penn fabrication to find out that they have a $75 minimum order amount. I'd end up with about 5 times the amount of extrusion I need, but I could probably slowly use it or sell it off to other people wanting to build a case. I also just emailed ecscase.com to see what their minimum order is. As far as crtvworks.com goes, their extrusions are too large for a fiberglass case, unfortunately. I appreciate the links.

peace,

russ