Louvers

General Composites Discussions Composites Talk
#1

Just wondering if any of you guys have any tips to making some Louvers (Vents). I found one DIY that turned out really good (IMO) but am wondering if anyone else had any other method. I need this to keep most of the water from coming inside the box, yet still need ventilation to keep some electronics cool. Any ideas are more than welcome.

Attached is the shape of the compartment I am trying to make. I figure either having louvers on the side or bottom. I don’t have much clearance on the top unfortunately.

I have began making a plug out of MDF so far and just need to add a fillet at the base and paint with duratech primer.
http://www.luxury4play.com/car-audio…ots-diy-2.html

#2

So this question is a bit different than the first one. First of all I have made a plug out of MDF and sealed it with Duratec Surfacing Primer, It looked pretty good, no gloss as it was a flat black. Well I laid up and decided to use Carbon to see if I would be happy with the finish on the outside using a standard layup, if not I could always continue and use it as a mold as intended. However, (I assume due to my wax jobs and little draft angle) I needed to demolish the plug in order to get the part off in one piece. I layered two layers of carbon in between 2 layers of thin fiberglass sheet as I new I needed to sand a fair bit to get the outside to look decent.

I ended up begining to sand the outside today and it is comming along just about as painfull as I was expecting. However, I ended up sanding right down to the carbon fiber layer and have dry spots now inbetween some of the weaves. I know I need to re-epoxy it, but don’t know what grit I should stop sanding at? Another option is I can always paint it and just live with that and possibly just do a design on the top (Which turned out pretty good) and leave it with the carbon look.

Or should I just stop wasting my time sanding the outside, and focus on getting the inside preped so I can pull a part out? I am kind of scared of this method as I don’t know if I will have the same issue as I did with the plug and not be able to get the part out.

Thanks for any help you guys can throw at me. I do plan on trying it again possibly once I get the rest of the project done and don’t have to worry about the time constraints.

Or I

#3

Your image seems to have almost perpendicular walls, that is zero draft. You need to have a good positive draft to allow the part to be pulled out. You also have sharp corners, how do you propose to get those? Sharp corners will almost always leave airpockets unless you have a radius at least 2.5-3 times the thickness of the reinforcement.

Duratec surfacing primer can be sanded, polished and compounded all on its own. You can compound it using 1000 and 2000 acquabuff compounds from hawkeye. In non A class molds you don’t need VE high gloss. When you compound the surfacing primer, you’ll get a nice shiny smooth surface, which you can seal with mold sealer and wax it to make your mold.

N

#4

It had roughly a 2 degree draft angle which I thought would have been fine considering it was only 3 inches high, but I guess I was wrong. The radiuses actaully didn’t turn out too bad, That was just a cad file to show the rough shape, The fillets on the bottom were added later with bondo, so I can’t really say whether or not they were larger than the fiber thickness.

I intend to do another mold/layup in the next few weeks and hope it turns out better (Plan to have a two part mold so that I can have 0 draft this time. Only thing is I am going to see if I can think of a way to make the mold out of metal to permit the use of the carbon pre-peg this time around.

Thanks for the info though Nash, Sounds like I should of kept going with the sanding instead of settling for the duller finish.

#5

In addition, I am wondering if you guys would happen to know what tempurture the West System 105 can withstand without issues. Wondering if I could possibly use a carbon/epoxy layup in the autoclave to do some prepreg? I tried looking on their website and haven’t really found a max operating temperture?

#6

Here is a link for the properties of WS 105. You will want to look at the HDT and Tg specs.

#7

Thanks very much Wyowindworks, exactly what I was after.

#8

we have made fiberglass louver,but yours shape are different

#9

pics, or it didnt happen… :slight_smile:

#10

Those louvers were made by a fellow on the forums here that goes by the name Roboloop. I was originally supposed to make them out of sheet metal, and just press the louvers in, but figured I would have a shot at composites.

I wouldn’t mind seeing your version of the louvers though bostartrade