Best resin expander, and fiberglassing advice???

sampson
10+ year member

CarAudio.com Elite
Hey whats up guys, Now that I have done a few fiberglass setups, I was wondering if I could get some of your opinions on resin expanders. Up until now I have been doing the classic... resin + mat, resin + mat, resin + mat, then bondo, sand, bondo sand etc.... Until finished. But after hearing the resin expander idea I did some research and found that people seem to be using everything for expander? I have seen aerosil, talcom power / baby powder, sawdust, the classic milkshake 2 X resin to 1 X bondo, as well as a few other ideas.

From your personal experience what has worked the best. I'm getting pretty **** good at fiberglassing and would like to try this new resin expander method and do it that way, to save time and $$$. From what I've heard it is a bit weaker, but not to the point where it really matters. Anyway let me know anything you want to post on the topic, advice would be awesome on what is the "best" expander to use, easiest to sand etc... Just anything you have learned in the past so I don't make those mistakes. Going for primarily sub enclosures here, maybe some kick panels, door panels, etc.. a bit later. But yeah any advice please throw it down, I'd love to learn by your mistakes instead of making them on my own //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif. Thanks a lot you guys-Sampson

 
first off the expander and resin mix is done on the inside of enclosures and isn't ment to be sanded down, i personally use arosil powder, pour in my resin, and keep adding the powder until i have achieved the correct consistancy, then i add my mekp

this will be used to pour into the insides of kick panels, sub enclosures, etc, and what it will do is jusat stiffin the resined fleece or trunkliner whichever you use, but on the other hand you cant expect to use grill cloth then a whole bunch of expander and call it a box,

the box will already need to have adiquate strength, this doesn't nesacarily strength but rather stiffin enclosures that already have a very large amount of strength and just need a bit more

 
yeah I understand the idea behind the aerosil + resin idea, with the comment of sanding down I was referring to the bondo + resin idea. That one I have read a few topics on and people say to sand down the high spots before it gets completely hard. But thanks for the input.

Would aerosil + resin be good if you only had the inital layer of matt down on top of the stretched fabric. By the sounds of it you are recommending more layers of mat, just wanting to clarify.

 
this will soley depend on how strong the enclosure with only your stretch fabric (depending on what your using) resined

if the enclosure is a bit weak still add a few layers of mat then arosil powder + resin for more strength

what im saying is if your using grill cloth (incredably thin) for your stretch fabric and plan on putting 2 mtx jack hammers in the box, arosil alone will not provide the strength your lookign for

 
if you are doing kickpods, you can seriously use some thin material (thinner than fleece) and just use a resin expander inside.

from my expierence its as strong as need be this way. only problem is it will resonate easily, so some liquid sound deadener is usually needed inside. the best part is thers almost zero sanding this way, and kickpods\doorpods usually dont need incredible strength.

if you are talking a sub box, you will definatly just want to do fleece+matt, and honestly, its usually cheaper to do fiberglass + resin for strength than a resin expander. reason is, resin is exponentionally more expensive than fiberglass (espically if you buy both in bulk)

i got a 5 gallon tub of resin for ~$85 and i got a ton of yards of glass (enough for like 10 large boxes) for like ~$30.

yea its easier to use less layers of matte and apt for expander in stead, but you use up TONS more resin that way. like 3x as much. its good for trouble spots, but i dont like it for entire boxes.

id rather just do 3 or 4 more layers of matte. i dunno, i glass fast. i did two entire trunk corner boxes in a day once. so its up to you. i find it cheaper just do do the extra layers. more labor, but cheaper.

 
awesome thanks for the info guys....req where the **** did you find 5 gallons of resin for 85$? I would love to get that much resin at that price. Where are you located at btw? Is it a special kind of cheap resin or something or whats the deal. Not trying to insult, but that is a really good price. Let me know.

 
EB General Purpose Polyester Resin for 85.00 for 5 gallons of it????

Is that what you guys are referring to? Is this the plae that req gets his resin??? Also how much does that weigh, and do they ship?. Go figure it is about as far away from me as possible while staying in the states. I'm up in Washington. Know of any good places up here?

....n/m just found that they do ship, but charge killer prices for it, know of any place like this in the Northwest? Thanks for the post.-Sampson

 
yea thats where i got it. im in NY, i think it was like $94 after shipping now that i think about it. maybe 100. i dunnaw.

even if it was $100 after ship, that turns out to be $20\gallon wich is $15 cheaper per gallon than i can get in NY locally.

 
just a tip on fiberglass enclosures. i have been using this Polyester fabric. is very thick and elastic. once you pour your first layer of resin it will be very strong since its Polyester material and Polyester resin, strong enogh for pods and if for sub enclosures, that plus like 4 layers of mat "shape dependant" its all youll need.

and if extra strength is needed mix some of the saw dust with the resin and lay it inside the enclosure.

 
Hey whats up guys, Now that I have done a few fiberglass setups, I was wondering if I could get some of your opinions on resin expanders. Up until now I have been doing the classic... resin + mat, resin + mat, resin + mat, then bondo, sand, bondo sand etc.... Until finished. But after hearing the resin expander idea I did some research and found that people seem to be using everything for expander? I have seen aerosil, talcom power / baby powder, sawdust, the classic milkshake 2 X resin to 1 X bondo, as well as a few other ideas.
From your personal experience what has worked the best. I'm getting pretty **** good at fiberglassing and would like to try this new resin expander method and do it that way, to save time and $$$. From what I've heard it is a bit weaker, but not to the point where it really matters. Anyway let me know anything you want to post on the topic, advice would be awesome on what is the "best" expander to use, easiest to sand etc... Just anything you have learned in the past so I don't make those mistakes. Going for primarily sub enclosures here, maybe some kick panels, door panels, etc.. a bit later. But yeah any advice please throw it down, I'd love to learn by your mistakes instead of making them on my own //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif. Thanks a lot you guys-Sampson

Hard to beat the ease of sanding plane old rage gold. I don't like using cabosil, or an of the like for finishing work. It's always been easier for me to just work all the wrinkles and everything out before hand. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 
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