fiberglass

We have a marine trader europa and on the top deck it originally had teak decks. however the person before us removed them and put another layer of fiberglass down. The fiberglass work they did is very very VERY wavy, to the point its almost impossible to sand. its a large area, would a filler work? any ideas or suggestions?

There are fillers that would work, but I don't know of one that would work as a floor surface, too. The existing floor could be sanded down some (or maybe a lot), the wavyness could be filled to a proper smoothness, then correctly glassed over.

Ken

Pictures would help. Why is it almost impossible to sand? Yes fillers could very potentially work. Without seeing it I am just guessing but resin with milled fibers or colloidal silica into the most severe low spots and then apply heavily wetted out layer of fiberglass mat to provide a level surface. It is smart to decide ahead of time how you want to finish it before choosing your type of resin (don't use epoxy if want a gelcoat finish). Many are using non-skid products you can roll on like "kiwi-grip" for these types of projects, the finish allows a nice look without having to fair the deck to a super smooth.

Filler could add a lot of weght up high.

I'd get a belt sander (or bigger) and grind off all the bumps and some more to really smooth things up. Then re-glass and paint w deck paint (exterior) and a light reflective color as I see you're in a sunny place.
Or if after sanding the deck is found to be very sound just paint after sanding.

Having just gone through this. . .

Nomad Willy said:

Filler could add a lot of weght up high.

I'd get a belt sander (or bigger) and grind off all the bumps and some more to really smooth things up. Then re-glass and paint w deck paint (exterior) and a light reflective color as I see you're in a sunny place.
Or if after sanding the deck is found to be very sound just paint after sanding.

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I had to cut off part of the rear deck as the POs had re-enforced part of the roof to accommodate a helicopter. They sprayed the entire deck with pickup truck bed liner, which also had to come off. I tried all sanders, to include a vibrating floor sander that I rented. I finally found the best performance with a duel action sander. The belt sander did not work so well and was hard to control.

If you are going to do a large sanding job, do yourself a favor and get a DA.

Gordon

Wavy? Why? If the PO'd removed the Teak and ground the sealant off w/o chewing up the underlying gel coat and fiberglass too much then the layer of new 'glass should be about as flat as the original structural 'glass. How wavy is it - in 32nds of an inch over what sort of spacing from hilltop to hilltop?

What's the finish surface now? Paint? Gelcoat? Applied non-skid?

I concur with NW, above. Sand down to something uniformly smooth, sound, and made of fiberglass. Assure yourself that the remains of the earlier fiberglass repair is well bonded to the original 'glass. I suspect you'll discover that the repair was put down over poorly cleaned/ground original 'glass and sealants. You may even find that the original screw holes were poorly cleaned and perhaps not filled.

Various tools will make this less painful.
Belt sander (3 x 21 is about all you'd care to hold on to while on your knees; 4 x 24 is 'way too much!).
Orbital sander (the 5" disc Dewalt is pretty dandy: DEWALT D26453 5" 3 Amp Variable Speed Random Orbit Sander)
Consider renting a floor refinisher's orbital/edge sander; much meatier and has wheels to make it easier to do the job. Floor Edger 7" Rental - The Home Depot
And don't eschew a Fein-type detail sander for the corners.

Then, if necessary, apply a thickness of 'glass, then a sandable filler for achieving adequate perfection, and gel coat. Remember the gel coat has to be of the type that will cure in air; it's got a wax in it that allows the polyester to cure.

Just a thought, but did you think of talking to a hardwood floor refinisher. I'm thinking their floor sander would smooth that out pretty quick. I would also suggest not DIY'ing using this method through. Unless you are a seasoned expert with the machine you'll go right through in no time.

Welcome to the forum! Filler in any appreciable thickness will crack over time when the roof flexes. Best to determine with a straight edge and a ruler how much you need to fill. It may be best to sand down the high spots, lightly sand the low spots to fiberglass, fill the low spots with fiberglass mat, and then cover the whole top again with one layer of bi-axial cloth and fiberglass.

Ted

Easier than you think

ziracuny,

Here are some pictures of the salvage job I undertook. I used Awlfare for filler. This is what the professionals around here suggested. I have found no cracks or other issues. I probably did not have to fill areas larger than one-inch by three inches and then, usually, no deeper than an eighth inch or so.

Gordon J said:

ziracuny,

Here are some pictures of the salvage job I undertook. I used Awlfare for filler. This is what the professionals around here suggested. I have found no cracks or other issues. I probably did not have to fill areas larger than one-inch by three inches and then, usually, no deeper than an eighth inch or so.

Click to expand...

Awlfare seems to work well as a skim coating (which is what you did). When it's used to will 3/8+" deep valleys is when you will have issues with cracking.

Ted

mbevins said:

Just a thought, but did you think of talking to a hardwood floor refinisher. I'm thinking their floor sander would smooth that out pretty quick. I would also suggest not DIY'ing using this method through. Unless you are a seasoned expert with the machine you'll go right through in no time.

Click to expand...

My vote....

and who cares if you burn through.

Epoxy down some new thin glass panels, fill and tape the seams, sand and paint or gel coat.

Has anyone given thought to using the RFB (rigid fiberglass board) that HD sells in 4x8 sheets? Sure, one side has little bumps but the other side is flat, dull white.

I use a lot of that stuff around our apartments. And yes, cutting it falls into the G10 category if you use a saw. The correct tool is a metal nibbler and Harborfreight sells an inexpensive power tool for less than $50. We discussed using this in another thread dealing with toilet area earlier.

I personally would not use it for decks.


Whatever it is...is great for bathroom walls...but I don't like it for much else...it just seems to be barely one step up from gypsum board. If I can crumble it in my hand...just ain't making it as they say.

foggys, I use the fiberglass sheets as sold by The Despot for use as wall coverings in restaurant kitchens and toilet rooms. Our Canadian friends say that the stuff sold up there for the same purpose is PVC.

I use the stuff for all sorts of things but not kitchens or toilet rooms: pop-in sunshades for boat windows; under-sink cabinet liner for waterproofing; pipe covers; shower ceiling; access hole covers on our trawler; roofing and trim on my wife's Little Free Library. I never use the pebbly side out; I normally sand the pebbles off to bond it, and sand the backside smooth for the show side.

The stuff is mostly gelcoat with a smidge of fiber. It's fairly brittle and low strength. I doubt, given its cost and intended use, that there's much in the way of UV resistance, though polyester resin in general is supposed to be pretty good. I don't think the shiny, pebbly surface would be much of a non-skid surface.

I think the stuff might well be tempting for exterior marine use but I don't think I would. At the very least, adequate bedding/bonding for full support, and adequate clamping (weights) to ensure that bond.would be problems to solve.

Others have considered using if for deck repair, too. Search this forum.

DHeckrotte said:

foggys, I use the fiberglass sheets as sold by The Despot for use as wall coverings in restaurant kitchens and toilet rooms. Our Canadian friends say that the stuff sold up there for the same purpose is PVC.

I use the stuff for all sorts of things but not kitchens or toilet rooms: pop-in sunshades for boat windows; under-sink cabinet liner for waterproofing; pipe covers; shower ceiling; access hole covers on our trawler; roofing and trim on my wife's Little Free Library. I never use the pebbly side out; I normally sand the pebbles off to bond it, and sand the backside smooth for the show side.

The stuff is mostly gelcoat with a smidge of fiber. It's fairly brittle and low strength. I doubt, given its cost and intended use, that there's much in the way of UV resistance, though polyester resin in general is supposed to be pretty good. I don't think the shiny, pebbly surface would be much of a non-skid surface.

I think the stuff might well be tempting for exterior marine use but I don't think I would. At the very least, adequate bedding/bonding for full support, and adequate clamping (weights) to ensure that bond.would be problems to solve.

Others have considered using if for deck repair, too. Search this forum.

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Brittle? Geez, I beat the heck out of the stuff and find it very durable. I can vouch that cutting the stuff with a saw will test one's mettle. But this is subjective for sure. Remember, the stuff is only 0.088" thick including the bubbles.

Your Canadian friends may well be using PVC because HD sells both and they do look somewhat alike. I have used the stuff for outside applications without problems.

But my suggestion for marine use pertained to using it where the surfaces are flat or close to it. Most likely the dull surface finish along with its color would require some type of overlay to make the job's appearance acceptable. But for sure, I would consider it instead of trying to manufacture a flat surface using just glass in non stress applications. Anyway, it was just an idea for whatever it's worth.

EDIT: Yes.....under sinks! I also use it in both kitchens and bathrooms. Sure hides a great deal. We were cost sensitive when we were upgrading all our older buildings to modern standards and our cabinets show it. Many look as good as new after 20 years others I had to gut the insides of cabinets. Depends a lot on the tenants, some are very good and some are a PITA. So a little bit of 3/8 plywood covered with RFB really shines and is not going to rot. Highly recommended for this useage.

Very brittle....cut it like butter with shears...can break off scored pieces by hand.


Sawzall would be huge overkill.


Not sure what you are using but the bathroom grade panels I have bought at HD or Lowes aren't anything more than a water resistant coating.



And yes I have used it for or helped with everal bathroom renovations including the last was my master head this spring.

psneeld said:

Very brittle....cut it like butter with shears...can break off scored pieces by hand.

Sawzall would be huge overkill.


Not sure what you are using but the bathroom grade panels I have bought at HD or Lowes aren't anything more than a water resistant coating.

.

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Window glass for sure in the brittle category. Those things that I can flex almost 90 degrees before snapping are far from being brittle where brittle is described in my Webster's New World Dictionary; having a sharp, hard quality, stiff and unbending, not flexible.

But back to decks, I have never done fiberglass work so I accept opinions from those who know more than me that this doesn't belong on a deck. Before I purchased a metal cutting nibbler, I used power saws, both my cabinet maker's saw and skill type saws. Both required fine tooth blades and were a BPITA. In addition to the cutting challenges, there was the dust.

I don't purchase bathroom grade panels, not sure if I know what you're referring to. If we need new panels in our apartments (19 of them) I fabricate them using whatever material is satisfactory. The RFB does a great job under sinks in both bath and kitchens as mentioned by DHeckrotte .

PSNEELD--

I never thought to cut this with shears. After reading your post I went down stairs to my basement and tried cutting a piece. Yes, it certainly does cut easily with shears......I hate using a saw on the stuff.

Foggy

I would think twice before deploying a floor sander. I rented and tried using a heavy vibrating floor sander with 40 grit. Didn't have much of an effect. I did not try a belt floor sander because I was worried it might get away from me and I would take off too much.

I have finished sanding and priming the entire topsides in preparation for painting. I have found that a dual action sander with 80 grit takes off plenty of gelcoat while allowing me maximum control of the device. My sander has both an orbital and rotary selection. While in rotary/disk sanding mode, I can take off tons of material. I use the vibrating/orbital selection for finer work.

This is the sander I use: Bosch 1250DEVS 6-1/2-Amp 6-Inch Random Orbit Sander with Vacuum Port

Gordon

Gordon J said:

I would think twice before deploying a floor sander. I rented and tried using a heavy vibrating floor sander with 40 grit. Didn't have much of an effect. I did not try a belt floor sander because I was worried it might get away from me and I would take off too much.

I have finished sanding and priming the entire topsides in preparation for painting. I have found that a dual action sander with 80 grit takes off plenty of gelcoat while allowing me maximum control of the device. My sander has both an orbital and rotary selection. While in rotary/disk sanding mode, I can take off tons of material. I use the vibrating/orbital selection for finer work.

This is the sander I use: Bosch 1250DEVS 6-1/2-Amp 6-Inch Random Orbit Sander with Vacuum Port

Gordon

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Hence why I said it was NOT a DIY project. A proper floor sander has belts. But if you've never operated one you'll never control it. The pros would make short work of a fiberglass deck in this state.

"I would think twice before deploying a floor sander"

You bet, BUT the "sand paper" as used on many floor machines is excellent for GRP work.

It is silicone carbide and the 16 or 20 grade does not clog when sanding green GRP.

Purchase it in sheets and cut the paper square , then use sanding disc adhesive to put it on a thick 2 inch sanding pad.

A VERY light touch is used and the corners on the disc will keep from digging in.

Green GRP is a fresh laminate that is an ongoing laminate build that has no wax in the resin and is air inhibited , so surface sticky when hard.

FF,

Great idea. I used an 8-inch grinder with 16 grit to get rid of the pickup truck bed-liner. Of course, using a grinder means I am only using the edge of the sanding disk and making a cut in the glass was always a danger. The floor sandpaper on my DA sander would have been a better, faster option with less danger of gouging the deck.

Gordon