fibergalssing ?

[SkiDiggity]

So today i went to fiberglass my footholds in for the second time now and the mat would not absorb the epoxy resin. This is frustrating if it is not one thing it is another. What am i supposed to use to glass these :censored: in!

:banghead:

shane

 

[shawn_NJ]

Fiberglass ChopStrandMat has a chemical binder that is dissolved by styrene in polyester and vinylester resins. Chop mat is not designed to be used with epoxy resin. Epoxy is for cloths without the chemical binder.

 

[Waternut]

Are you using the thick resin or regular resin? Glass doesn't just absorb resin like water in paper. You do have to push it in there some.

BTW - I've used mat with epoxy resin without any problems at all.

 

[SkiDiggity]

this mat is pretty thick and i am using the thin resin from Us Composites.com and yes i tried pushing it in there it would not take it at all i sat there with the paint brush dabbing the sh** out of it for like five minutes and it was still all white when i held it up.

 

[shawn_NJ]

this mat is pretty thick and i am using the thin resin from Us Composites.com and yes i tried pushing it in there it would not take it at all i sat there with the paint brush dabbing the sh** out of it for like five minutes and it was still all white when i held it up.

It turned into a stringy mess? Thats normally what happens. Try using some polyester resin and watch how well the mat wets-out and bends to contours.

 

[SkiDiggity]

it did not even go stringy and you can't use polyester on a 94 superjet it wont stick because the hull is not fiberglass that is why this is my second time glassing these in i used polyester the first time and everyone said it would not work so i ground everything off .

 

[shawn_NJ]

it did not even go stringy and you can't use polyester on a 94 superjet it wont stick because the hull is not fiberglass that is why this is my second time glassing these in i used polyester the first time and everyone said it would not work so i ground everything off .

They are correct, polyester is not compatible with SMC. You should use a fiberglass cloth material for that application. Will work 100x better.

 

[Waternut]

If you were dabbing it on chopped strand mat and the mat wasn't sticking to the brush and pulling up into a big stringy mess, then the resin has got to be screwy. The resin should at least be somewhat tacky. Sounds like you're dabbing the cloth with water...

Polyester resin can be used on SMC. It just doesn't stick very well and doesn't have the bonding strength of epoxy resin. If you riveted the holds in place, the resin is really there to help keep water out and provide that little bit extra strength. You won't yank 10-15 rivets out with your feet.

 

[SkiDiggity]

so i should buy some cloth then instead? and it is as strong as mat?

 

[WFO Speedracer]

Yes just use cloth,you can always use multiple layers of it.

 

[Breese08SJ]

If its Is done correctly IE. multiple layers to build up the thickness, laid at 0, 45, and 90 degrees it will be much stronger than the chop mat. Most people seem to think chop mat is strong but the resin to glass ratio is out of this world, way to much resin. Excess resin tends to make the composite matrix brittle and prone to cracking... Chop mat provides considerable thickness in very few layers this is why most use it... Take Shawn_NJ's advice and get yourself some glass cloth and all of your problems will be solved.

 

[kraqus]

I used 2 layers of 12 oz Biax which is a mix of cloth and mat strands if you will, hardens super strong IMO.

http://www.x-h2o.com/showpost.php?p=837846&postcount=27


Benny

 

[shawn_NJ]

I used 2 layers of 12 oz Biax which is a mix of cloth and mat strands if you will, hardens super strong IMO.

http://www.x-h2o.com/showpost.php?p=837846&postcount=27


Benny

Yep, the mat in biax is stiched and does not have the chemical binder that regular CSM has. Its only a 3/4oz mat (not 1.5oz) so it soaks up 1/2 the resin, but still allows the thick 12oz (or 17oz) bias roving to bond well. Works excellent with epoxy, for quick thickness buildup and is insanely strong if laid up right.

If you want to save $$, even a few layers of 6oz-10oz cloth would work just fine. 10oz plain weave is nice to work with.

 

[Waternut]

Just remember the cloth mat from your local auto store or walmart is considerably thinner than mat and will require at least 2 layers to equal the same thickness of mat.

 

[SkiDiggity]

well i do not know the thickness of my mat but what i ended up doing was splitting the mat in two and it soaked up the resin right away i did a few layers that way and it seems fine now.
Thanks for all the advice guys.
Now i am on to turfing never done it before and i bet it is going to be a.....wonderful experience from what i have read.

Thanks,
Shane