A different PMF,will it work?

[Onebad06vtx]

Instead of glue and canvas,with using penetrating fiberglass resin and canvas work?
Then several coats of paint.
I figured that apply a coat of penetrating resin to the wood then lay the canvas before the resing sets up.
Then apply several more coats of resin.

[tony.latham]

Instead of glue and canvas,with using penetrating fiberglass resin and canvas work?
Then several coats of paint.
I figured that apply a coat of penetrating resin to the wood then lay the canvas before the resing sets up.
Then apply several more coats of resin.

Fiberglass resins are made for fiberglass cloth. Why not use the real deal? Fiberglass is cheap. But you’ll have to use epoxy with foam. Easy peasy.

Tony


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[swoody126]

Instead of glue and canvas,with using penetrating fiberglass resin and canvas work?
Then several coats of paint.
I figured that apply a coat of penetrating resin to the wood then lay the canvas before the resing sets up.
Then apply several more coats of resin.

Onebad06vtx, "fiberglass resin" as most think of it is not intended tor application to wood and is not a glue as such

it is intended to be used to encapsulate glass fibers(chop'd strands n cloth and matting)

for use w/ wood epoxy is the product that is compatible with wood and can be used as a bonding agent

IMHO you'd be better off just doing PMF as designed

sw

[tony.latham]

IMHO you'd be better off just doing PMF as designed

Why PMF? It sometimes bubbles. It often looks like heck... it's not much cheaper than the real deal.





Tony

[Pmullen503]

I have to agree with what's already been said; if you want to use resin (epoxy or polyester) you should use glass cloth. I would not pre coat your wood with resin and expect to lay cloth over that while it's still sticky. Smoothing out the glass will be a nightmare. Limit any precoating to end grain only and let it cure, sand and then cover the rest. A slow cure, low viscosity resin win penetrate the plywood enough.

You'll still have to paint or varnish the glass for UV protection.

[KCStudly]

Cotton cloth will not go transparent, so will not show whether the resin has soaked through to the substrate adequately. Whereas, the glass cloth will go transparent when the resin has saturated through to the wood, so acts like a quality control feature during application.

Epoxy and glass
-or-
canvas and glue/paint

Heed Egon's advice and "never cross the streams".

[RJ Howell]

I've done both systems and find doing either well ends up costing very close to the same. Applies only if purchasing all the goods. That's the only reason IMHO to go one over the other cost wise, getting product cheap or free.

I'm sold on FG over PMF for durability, visual appeal and ease of working with. That's according to my ability to work with either, your experience may differ.

If you are going to mix systems I do suggest to do trial samples first. I did many (2 dozen I think) before I decided a system I liked. Probably 20 of those were PMF and 3-4 were FG.

[twisted lines]

Epoxy
That should keep the pounds down.
But the dust, still cleaning from #1

[tony.latham]

...and find doing either well ends up costing very close to the same.

As I've often said, the P in PMF is misleading. And I think that's what sucks people down the rabbit hole.



Tony

[twisted lines]

It says post, can I post the canvas I have stored here

[MickinOz]

I reckon the way to go is epoxy and fibreglass.
However, I do disagree that the 'P" in PMF is a misnomer, for Aussies anyway.

Seal timber with the mix Bondall 4L Marine grade varnish = $99
Zinsser "stick like sh** to a blanket" 3.78L Coverstain primer =$95
Taubman's 4L water based 3 in 1 primer sealer undercoat = $75
Top coat water based paint such as Taubman's Sunproof 6L = $75
Wagner heavy duty canvas 8oz drop cloth $4 per square metre.
Brushes and rollers - $25?

Turps $5 / L
Water $3.50 per kL here in South Oz.
So I could probably easily PMF a trailer for about $440.


5.3L International HT9000 kit = $250
Pumps to suit the 5.3L kit = $70
Thinners 1L = $46
Dynel 104gsm (3.5 Oz?) woven cloth intended specifically for epoxy sheathing - $22 per square metre.
Rolling out tool = $17
Say you need 15 square metres of cloth.
$330 for cloth.
That's going to need a bit over a gallon of resin to wet out, I think, so the 5.3L kit is probably the right size.
So about $720 for epoxy and cloth. (Without topcoat.)
Rustoleum 1 gallon bedliner kit for topcoat = $224

Money-wise, the 'P" in PMF holds, it's probably half the price of epoxy and fibreglass, here in Oz.

BUT, in my eyes, only half as good.

[tony.latham]

So I could probably easily PMF a trailer for about $440.

Crazy prices down there!

I glassed my teardrop in 2018 for less than $250–-and still have a lot of epoxy left. I suspect it would cost over $300 in today's world.



Tony

p.s. Mick: Stay warm down yonder where the sun's pointing at you... it's 10ºF up here this morn at 45º north latitude...

[MickinOz]

A balmy 26C here today. About 79F.
Didn't realise how far north you are. 45 degrees! No wonder it gets a tad chilly.
I'm at 33 south, so far closer to the equator than you.

[tony.latham]

I'm at 33 south, so far closer to the equator than you.

:thumbs-up:

Tony

[Mark Gunter]

For me, the big misnomer in so-called PMF is the “F” because combinations of cotton cloth, adhesive & paint has nothing whatsoever to do with Fiberglass lol.

All of my experience with fiberglass has been of a professional nature doing auto body repair on header panels and on corvettes. I’ve had excellent results with fiberglass.

My only experience with so-called PMF has been on my current camper build, a 11.5’ by 7’3” standy. I decided early on that I didn’t wish to do Fiberglass over that large a project. So far, I’m extremely pleased with my choice of skinning this tank with canvas & paint. Just finished the exterior this week and it looks great. Only time will tell regarding durability.

If the exterior holds up as well as I believe it will, I’ll be a proponent of so-called PMF … but with respect to any who prefer “the real deal.” What I wouldn’t do is take the approach OP suggested. Stick to one or the other.