cabosil or chop mat for stringer plywood

[nickfara]

I am confused, in replacing transem plywood, my boat guy told me to use 2 layer of chop matt to hull before installing first plywood, but the guy at fiberglass store told me to mix cabosil with polyester in a paste form and do away with chop mat. Any reasoning if one techniques better than the other

 

[HUMPH]

3 new threads? You may want to delete a couple of these...

 

[nickfara]

Hi
I was not sure which was right place, classic, fiberglass or maint., let me me know which to keep
thank you

 

[nickfara]

I just tried delete, I see edit/delete but no actual delete button found. Let me know if I missed it
thanks

 

[fwebster]

Cavisil is used to thicken resin and has very little if any tensile strength. Do not ever believe anything the guy who advised using Cavisil for a structural repair tells you again. And to confuse you even more, I would use fiberglass cloth, not chopped mat.

Cavisil can be used in very thin coats for fairing the repair when you are done.

 

[Prater]

I find that chopped mat is easier to work with and is recomended on transoms for the first layer. It will easily fill voids and you can shape it easier after you wet it out. The one thing to remember about the matt is that is not to be used with epoxy resin, it has many short strands that are held together with a binder that diosolves in resin. I would use cloth as layers since it adds strength. You can alternate the two, matt and roving, together to form a good strong structure. If you are doing it yourself get a book from the library on fiberglass repair.