Fiberglass vs PMF cost estimation

[leblanda]

I did some cost estimation about Fiberglass and PMF in my location Quebec Canada.

So the goal is to do a foamie (more an enclosed utility trailer than a camper) 64 inch width x 130 inch length x 72 inch height.
A total of 302 sq feet with the bottom that need to protected since it will be a removable pod to be bolt on my existing utility trailer

Here's the price I found near by
fiberglass 6oz 38 po 8.75/yard
epoxy 99.60$/gallon about 50 sq feet coverage
Minwax polycrylic 60$/gallon about 250 sq feet coverage
titebond2 42$/gallon unknow coverage

Epoxy fiberglass
Cloth 38 yards 332$
Epoxy 6 gallons 604$
Total 936$

Polycrylic fiberglass
Cloth 38 yards 332$
Polycrylic 2 gallons 120$
Total 452$

PMF
9x12 drop cloth 180$
TitebondII 2 gallons 84$
Total 264$

I'm looking to finish the inside with 1/8 Luan.

I was going to select polycrylic fiberglass since I read somewhere that there is not a big difference in cost for fiberglass vs PMF.
But regarding the result here I will go for PMF!

Any thought?

Thanks Dan

[OP827]

I never heard of minwax polycrilic clear coat used with Fiberglass in lamination.
6 gal of epoxy vs. 2 gal of TBII, did you get the numbers right? Epoxy is 100 percent solids, while TBII is about 50 percent solids, so the math does not seem right. Normally Fiberglass epoxy lamination takes 50/50 by weight of epoxy and cloth.

[RJ Howell]

Most of what I see hear is what you have to pay in Canada for goods. I was less than half your FG costs for nearly the same sqft of area. Yes, done on the down-low PMF is certainly cheaper to do. I didn't like the HF canvas and really liked the Duck cloth for a couple more dollars. I had some issues with Titebond, others have had none and when with a stronger primer and quality exterior paint. Doing this, I found little cost difference.

We travel quite a bit into the Atlantic Maritimes (well.. did..) and find very few things to be equal or cheaper than in the states (with exchange calculated in). Also believe your calculation on Epoxy is high.. I bought a 3 gallon kit and had 1/2 gallon to spare.

[leblanda]

I never heard of minwax polycrilic clear coat used with Fiberglass in lamination.
6 gal of epoxy vs. 2 gal of TBII, did you get the numbers right? Epoxy is 100 percent solids, while TBII is about 50 percent solids, so the math does not seem right. Normally Fiberglass epoxy lamination takes 50/50 by weight of epoxy and cloth.

For Polycrylic fiberglass vs epoxy look here

[youtube]https://www.youtube.com/watch?v=WuEHe6cmnp4[/youtube]

For the Math I don't know! the guy says it is 1 gallon for 50 sq feet.
Can you instruct me how to do the math?

Thanks

Dan

[OP827]

For the math on epoxy Fiberglass I would take same weight for epoxy as your glass cloth and add about 15 percent for epoxy wastage. So if you have 100 sq.yards of 6oz cloth then you would need 100x6=600oz plus 15 percent wastage for total of 690oz or approx. 5.5gal of epoxy. This amount is based on 50/50 optimal layup of Fiberglass. Wastage can be more or less depending on substrate, methods and experience.
https://theepoxyexperts.com/conversion-table/
I have no experience with PMF, but the ballpark amount would probably be in the same order of magnitude, but on a higher side for TBII, maybe closer to a double the amount vs epoxy due to it's evaporation, heavier canvas vs glass cloth and need for multiple coats required as being half solids content.

[OP827]

Thanks for the polycrilic Fiberglass video link. That was interesting. Obviously for structural purposes epoxy is a better choice but for not load bearing surfaces this polycrilic method might be attractive as being non toxic application and might provide a bit more refined surface than PMF. Epoxy does have limitations due to toxicity, I wouldn't do epoxy lamination in my shop without substantial ventilation arrangements. It is a health risk. Epoxy is ok for doing it outside during summer though.

[Noc3]

has anyone done polyurethane over canvas? I'm guessing the canvas would just drink up too much and get heavy...but it may be really strong!

[GPW]

Hey Noc , I believe anything with a solvent that evaporates gets lighter as it dries …. Unlike fiberglass/epoxy resin which just chemically dries … And from many years making airplanes and boats ( little ones ) , we found the fiberglass cloth was normally lighter than the resin . Once the cloth was completely “Wetted” , any more resin only added unnecessary weight … Polyester resin can be used on foam surfaces after a simple glued on paper ( or wood ) layer first … Epoxy must be protected from sunlight … And of course for ultimate Strength , Kevlar , Spectra , Hemp , or one of the new miracle fibers … Pricier but STRONG !!!

[tony.latham]

And of course for....Hemp...or one of the

Glenn:

Is there a new laminating material made from hemp now? First allusion I've read about the stuff for that purpose.

Tony

[GPW]

Tony, I was reading about a fiberglass , er, Fiberhemp glass that was supposed to be pretty strong … I don’t know ??? Will try to find it again … It’s all cellulose eh ??? ( not the hippie stuff … )

[GPW]

https://www.youtube.com/watch?v=m77F2Z-FfnU

[GPW]

With so many new materials available , we’re bound to find something we like eh ?

[GPW]

Now then , as far as the long term cost goes , we’re going on out Eighth year of the Foam Stream living totally outside , and through all kinds of nasty weather and storms … The results … It got dirty … With a good Wash and chasing the little critters out of the door areas , we’re ready to go … And yes, the fully surrounding drip edges really DO make a difference !!! ( Thanks to George for that!!! )

[rowerwet]

Now then , as far as the long term cost goes , we’re going on out Eighth year of the Foam Stream living totally outside , and through all kinds of nasty weather and storms … The results … It got dirty … With a good Wash and chasing the little critters out of the door areas , we’re ready to go … And yes, the fully surrounding drip edges really DO make a difference !!! ( Thanks to George for that!!! )

Same here, my foamie is also full time outside and essentially ignored. Rain, sun, ice, snow, my kids climbing on it to sit on the roof, it's unchanged. Same with my foam kayak fleet. I normally store them outside year round, on top of my firewood racks. They get beat up from use, but not from sitting out exposed.

Fiberglass needs a UV barrier, and that often needs maintenance, house paint makers put plenty of research into that already.

[GPW]

Row’, after my first foamie (PMF) went through a horrible Hail storm that Broke and ruined everything else , The Foamie was dented like a golf ball… But after a week in the sun , it all pretty much went away … Healed !!! I know other covering would have been much more damaging … local plastic signage was shattered, Fiberglass cracked and crazed from impact … metal panels dented forever ( cars ) … Only PMF recovered on it’s own , with a little help from the Hot summer Sun …. That was enough of a Test for me !!! PMF proved itself ….time and time again …
And really , a Kayak is a much TOUGHER test of these materials …. If they survive that , a trailer should be no problem at all eh …