this sounds crazy?

[maagee79]

I was told today by a body man that fabric or cloth like a sheet could be used in place of fiberglass to seal a floor or other areas of a boat that needed water proofed. Sounded crazy to me but he said it would do the same thing just not provide the strength of glass. Any comments?

 

[Cheetah 210es]

Re: this sounds crazy?

Not so crazy. HMS Endeavour was refloated after hitting a reef using a sail fother stretched around hull to temporarily seal it.

 

[zymox]

Re: this sounds crazy?

That is correct. It can be used to do just that but as you already mentioned you won't get the strength of the glass. One more important thing to think of is that the polyester has to bond to the fibers. It's not all material that can be used for this and just to make an example: you could use dyneema fibers which is one of the strongest fibers known for a super duper laminate, often used in bullet proof wests but unfortunately the polyester just wont stick to it very well and then the laminate is worth nothing.
Polyester in it self doesn't have much of strength at all. In fact if you toss a piece of it to the floor even if it is half an inch thick it will shatter like glass.

Car enthusiasts has used your mentioned method for years to do their speaker boxes to look futuristic. A ring, a frame and a very stretched fabric. In fact I will try it to do a panel for my gauges using this method when it comes to that and then I will do a die out of it in polyester/glass.

 

[kfa4303]

Re: this sounds crazy?

I think the car guys like to use felt for their stereo boxes because it's fairly strong and soaks up the resin so well. You'll hear about people using all kinds of weird things with fiberglass like manufacturers using paper towel tubes as forms for stringers and all kinds of other strange stuff. As zymox said, it's the combination of the resin and glass that ultimately does the work, not so much what it's put over.

 

[Bondo]

Re: this sounds crazy?

I was told today by a body man that fabric or cloth like a sheet could be used in place of fiberglass to seal a floor or other areas of a boat that needed water proofed. Sounded crazy to me but he said it would do the same thing just not provide the strength of glass. Any comments?

Ayuh,.... The Strength is a Big issue,....

It'll be as strong as a wet sheet....

As noted, it'd make a Great mold for buildin' a fiberglass piece...

 

[maagee79]

Re: this sounds crazy?

Do u think it will still bond to the surfaces?

 

[oops!]

Re: this sounds crazy?

why are we doing this?

fiberglass matt, is really cheap.......did i say cheap , what i ment is it is as cheap as any other product you can use.

car guys use fleece, like a fleece sweater or hoodie.

if you do not use the correct product, you are relying on the stregnth of the resin to carry you, and as mentioned, resin is brittle.

to reinvent the wheel over 20 bux isnt really worth it imho

 

[86 century]

Re: this sounds crazy?

I have a buddy that does highend car audio. He uses fleece only for low pressure boxes any thing that is going to hold subs he will build a wood box the make it pretty with glass.

 

[oops!]

Re: this sounds crazy?

I have a buddy that does highend car audio. He uses fleece only for low pressure boxes any thing that is going to hold subs he will build a wood box the make it pretty with glass.

yep......polyester fleece for low pressure and glass for high pressure like bass bins.........some of those guys are real magicians with shapes

 

[evolution1985]

Re: this sounds crazy?

yep......polyester fleece for low pressure and glass for high pressure like bass bins.........some of those guys are real magicians with shapes

That is indeed correct. I have lost count of how many enclosures that I have made when I had my shop. I can say yes It will be waterproof, but the moment you drop something on it like an anchor, it will crack and leak water. as mentioned above thats a great way to make a shape that you normally couldn't with out extensive shaping with foam and plaster. But to add strength, for instance in a box running two 15" woofers we use mat over the frame and often or not its an inch or nearly two thick and weighs about as much as the starship enterprise. I have very limited hands on knowledge of any marine application, but what your describing has really no place on a boat. the first time the bow lifts out of the water and smacks back down what ever you had done will crack or worse. Most circumstances where that application is used without the fibreglass is for what I call a "show pony", all look no go. for instance a customer brought in a box that he had bought from a show car that was getting parted out, looked great, well made for what it was. He bought a couple of comp subs whacked them in and during the tune the box was flexing then pretty much shattered. to add insult to injury over the resin and felt was bog (bondo?) to get it all smooth. the fleece or nylon that is used is purely to give it shape, the resin seals the shape allowing paint and stiffness. As oops has stated why reinvent the wheel, fibreglass mat is really easy to work with once you have a go at it, the resin can be a pain tho.