Fiberglass cloth

[rhtrades]

Does anyone have a Fiberglass cloth size/recommendation for laying a deck?   chop strand or woven?   
Thanks.

[billy626]

Currently doing my 5th rebuild, and I've always stuck to three layers of chopped strand mat. Easy to lay, easy to wet out, and plenty strong. You could go a few layers of 1708 biaxel cloth, but that is more structural and would definitely be thicker.

[rhtrades]

Thanks for your reply.  I just read you shouldn't use Epoxy Resin with Chopped Strand??  So, the West System 105, 205 won't work to wet it out?  Is this true?     

[dbiscayne]

1708 is available everywhere and seems to be a good weight.
what are you using for a core material and dimensions of unsupported spans? If plywood, thats where the strength is coming from assuming its a decent thickness, just need to seal the wood really good and glass on top to protect from impacts. I had a 5/8" plywood deck last over 15 years w 2 layers 1708 on top and only epoxy resin on the bottom no glass, key is to let the wood breathe/dry out all the time. Had a few soft spots show up but that was my fault, screws, chipped glass, etc, letting moisture in. Coat the wood w thinned resin, then again w straight resin top & bottom, then glassed the top.
If coosa, nice strong material, have had success w 2 layers on top & 2 on bottom of 1708 but thats probably overkill.
Plascore, Nydacore, all the plastic honeycomb, this stuff is really good when used in the right application. Personally have used a lot w the same layup as coosa and it is plenty stiff/strong even when spanning decent gaps. Could argue that it needs more impact protection on top but for my use 2 layers has been plenty. Manufacturer has said only 1 layer needed on top w something like 1708 to provide enough stiffness but that won't give you much impact protection.

[dbiscayne]

CSM that is “Powder Bound” is compatible with epoxy but “emulsion bound” mat is not. The emulsion bound mat requires the presence of styrene (only present in ester resin systems and not epoxy) to property dissolve the binder and as such, emulsion bound mat will not wet out properly with epoxy resin.

[billy626]

@discayne's comment on the type of core makes a great point - really depends on the material you're using. I've always used plywood decks, soaked with resin front and back before laying glass over the top - exactly as @discayne mentioned.

1708 will certainly do the trick - thicker and will provide great strength. I've always used epoxy resin for all of my fiberglass work. Make sure whatever you use as your final layer has wax. Not sure what your'e doing with the floor, but the wax will create the hardened, finished layer. Epoxy without was is great for continuing to add layers / materials for good adhesion.

[rhtrades]

Thanks @billy626 and @dbiscayne for the quick replies and for this helpful info and questions.

I'm using Divinycell H80 PVC Foam as a core.  i've read good things...not as strong as coosa and wood, but it won't rot.   

I did not know about using wax with epoxy.  Will that then take Gelcoat well?  I know for the final layer of Gelcoat, I need wax....

just as an fyi (not sure if either of you have experience with it) but I came across this Gibco Flexmold stuff that will create a diamond pattern in gelcoat.  Its expensive so i'm only purchasing a 1ft x 1ft piece and will only gelcoat in sections.   

[billy626]

@Rhtrades - Never heard of it, but just did some research quickly. Do they make a reusable product that I'm not seeing? From my understanding, their product is a patch that covers nonskid in 1ft by 1ft areas - not a mold that can be pressed into gelcoat, then peeled off to be reused. Here is the video I found on their product:

https://www.youtube.com/watch?time_continue=77&v=ff2QzCEMxAE&embeds_referring_euri=https%3A%2F%2Fgibcoflexmold.com%2F&source_ve_path=MTM5MTE3LDM2ODQyLDIzODUx

It sounds like you are hoping to be able to reuse that pattern and do that over and over again across your floor, but I don't think thats possible (to the best of my knowledge - I can certainly be wrong here)

With regards to the wax - definitley don't add wax to the epoxy if you are planning on gel coating the deck. non-waxed epoxy will be tacky, then non-waxed gelcoat (will bond well) followed by your final layer of waxed gelcoat

[rhtrades]

Thanks a lot @billy262 for the Epoxy and gelcoat tip. 

regarding this flex mold...below is the link to the video that i first saw on this, saying that it is a sheet that can be used over and over again. 

https://www.youtube.com/watch?time_continue=157&v=aoOtHe4g9m0&embeds_referring_euri=https%3A%2F%2Fduckduckgo.com%2F

It's about $75.00 for a 1ftx1ft sheet so hopefully it does what i want it to....

[billy626]

@rhtrades very interesting! Never seen such a thing. Probably won't be fun to go a large area, but could be worth it!

[rhtrades]

no probably won't be fun....in any of the deck cores you've replaced, have you ever epoxied back the old non-skid that you cut out, if it were in decent shape?  I am considering doing that in a large section....wondering it it will blend in well with the other parts of the deck that i glass over and gelcoat