Fiberglass resin question

[LuckDay]

Happy Labor Day my boating friends!
So a few years ago I replaced an entire floor and stringers and transom in a 17ft tri hull outboard powered boat. When doing the floor I encountered as the resin over the fiberglass deck cured, there was a waxy substance I had to sand and chemically remove before deck paint went on. I’m getting ready to perform this chore again but I’m having trouble finding info on this subject again. It’s been 7 years since my last turn at the sealing a floor. My goal is to try a color matched truck bed liner (tan) for the deck on my 14ft runabout. Since the boat top and hull are separated - I can get right in there and spray after scuffing up the deck. Is the waxy “cream” of the old style resins no longer an issue? I may not be describing it properly but 7years ago- I knew everything there was to know about resin. Today- not so much.
Thanks!
Luckday.

 

[tpenfield]

Polyester resin often has wax mixed in to provide a barrier to air while the resin cures. The wax 'floats' to the surface of the resin after application providing the barrier. It sounds like that is what you are referring to(?) The are resins that don't have wax mixed in are typically used for laminating multiple layers or bonding things together.

Not exactly sure what you are doing this time around, but maybe posting a few pictures will help with responses.

 

[LuckDay]

Polyester resin often has wax mixed in to provide a barrier to air while the resin cures. The wax 'floats' to the surface of the resin after application providing the barrier. It sounds like that is what you are referring to(?) The are resins that don't have wax mixed in are typically used for laminating multiple layers or bonding things together.

Not exactly sure what you are doing this time around, but maybe posting a few pictures will help with responses.

Thanks. No pictures as of yet. Just trying to put together the items needed to do the job. I remember there were two types. For lack of better terms it was wax and no wax. I went above and read thru a really good sticky about materials and it all came back just as you said.
Thank you. SN the floor is out and so is the transom. I am laying out the new transom now and recovering from a mini heart attack after going to my local lumber yard and paying $400 for a single piece of 3/4” and 1 piece of 1/2” marine grade plywood. (4’x8’) Add in stainless steel screws and wood glue made for water and you’ve got a big ole bill for a small project.
Amazon has a lot of material for glassing on there but doing homework for the best products for the best price. Locally the West Marine epoxy is quite expensive. If I wait a few months the cost will drop. Boating in New England.
Luckday

 

[todhunter]

Ouch on that price. If you have to buy more wood, save your money and just buy exterior grade ACX radiata pine plywood.

 

[Chris1956]

Sourcing resin and glass from Amazon can save you 1/2.

Clamping the new transom into place, to bond with the hull, while the resin sets is probably the most critical item.

 

[tpenfield]

Don't tell anybody, but I use exterior grade plywood instead of marine grade. It is pretty much the same, the veneers are just not quite as good at marine grade. Same permanent adhesive.

'Greenwood XL' and 'Perma Panel' are a couple brands of the rot-resistant plywood that boat manufacturers use.

 

[tphoyt]

Agreed on exterior ply.
A true marine grade will have no voids between the ply’s. If you were building something for great strength that’s a bonus but not so much for what you’re doing. I made a 18’ skiff 15 years ago with spruce 2x4’s and 3/8 exterior ply for sides and 3/4 for the bottom and with keeping up on paint it’s still as strong today as the day it was built.

 

[KJM]

"Locally the West Marine epoxy is quite expensive." Polyester resin is cheaper and will work just fine unless you are putting it over already existing epoxy resin.

 

[stresspoint]

keep it to yourself , i only use exterior grade ply as well Shhhhh, .

still not cheap to buy and i use lots of resin to seal it.

FWIW ,i did a build about 5 years ago and did not complete it , all the glass work was done and it just needs fit out.(found a better project )
i used very cheap second hand exterior construction ply (i had a few sheets given to me after a privacy wall was de constructed) , 5 or so years of being out in the elements and its still as solid as when i laid it up.

i coated a few good coats of un waxed poly resin and allowed it to cure.
after cutting the shapes i coated the areas again with more resin.
once the lay up was completed there was a few good layers of CSM and rovings so the ply has basically never been exposed .

no way people should be spending big $$$$$ on marine ply when if the job is done correctly there will be enough resin to seal the wood and the lay up will be the strength.

 

[racerone]

I use West System epoxy.---More beer tokens I know.------I can no longer tolerate the smell of the polyester stuff.

 

[stresspoint]

I use West System epoxy.---More beer tokens I know.------I can no longer tolerate the smell of the polyester stuff.

i too am over the smell of polyester resin, one thing i learned long ago was that epoxy resin is very poisonous ,i believe more poisonous than vynalester (spell check) which most fiberglass people a scared to use, that does not stop me from using it , i just be sure to use the correct protective gear and avoid getting it on my skin.
all fiberglass materials are harmful in one way or another , it is just a matter of being aware of the health risks and use appropriate PPE.

 

[tpenfield]

If you want a real chemical warfare smell, try Vinyl Ester resin

 

[LuckDay]

Thanks for all the replies people. Love it. I ended up using an AC plywood for most of the project. The marine grade stuff is nice but I decided to save it for more important pieces. You’re right 100% on sealing properly is most of the battle.

Honestly my 14’ boat here lasted all these years with what ever was the cheapest wood StarCraft built it with in 1970 then she will last another 50 years with the wood actually sealed properly. Pics are from before the disassembly. It should be ready for spring 2024 or earlier but New England boat season is quite short. Water temps already in the low 60’s.
Thanks again!
Luckday

 

[tphoyt]

Here’s my rig with a fresh coat of paint and ready to go back on the hook.
Tight lines