Best fiberglass to use on wood teardrop?

[stevef22]

Hi all, Learning about fiberglass on wood applications. Very popular in boat construction. Looks to be a great way to make outside of teardrop shine and add strength.

Watched about 10 videos on youtube on the process.

Anyone here have expirence with fiberglass? How much would it cost to fiberglass a 5' wide X 8' long X 4' tall wood teardrop?

Any resources for quality fiberglass / resin etc would be great as well.

Just here to learn and soak up information.

Thanks so much for the help.

[rowerwet]

I build plywood boats and use marine epoxy to make them waterproof.
Epoxy coatings will need a UV protection layer. The easiest is paint, but if you want a clear coating, varnish will also work.
There are newer epoxies out there that are not as toxic and petroleum based. This one from my favorite site has a UV blocker built in http://www.duckworksbbs.com/supplies/ep ... /index.htm It smells nice and shouldn't have the alergic problems of regular epoxy.
How long the UV inhibitors last, I don't know.

[stevef22]

Thank you for the reply. Im sending an email to Duck Works asking about UV resilience.

Do different resins have UV rating like regular human sunblock? That would be nice lol. ( 45 SPF, 90 SPF etc. )

Thanks again for feed back. Will keep everyone posted what I hear back.

If anyone has a favorite fiberglass resin please share.

Thanks again.

[tony.latham]

I'm a fan of the Raka epoxies: http://www.raka.com/index.html They make a UV epoxy that I'd probably use but don't have any experience with.

I built a cedar-strip canoe that has two coats of a high-grade (UV resistant) spar varnish over the fiberglass/epoxy (and that's the norm for a stripper canoe) but my teardrops are sealed with epoxy and covered with aluminum.

Raka says you need further UV protection over their UV epoxy. Steve Fredrick, in his Teardrop Shop Manual suggests you give a woodie camper a fresh coat of UV varnish over the epoxy every other year if I recall (or was it from an email his sent me during my first build?)

Cedar strip canoe builders use 4-6 ounce cloth and I think the 6 ounce is standard. But keep in mind, it's adding strength that shouldn't be needed in a classic teardrop construction. If I were glassing a teardrop––to ensure the wood fibers were sealed––I'd use cloth that's no greater than 4 ounces perhaps even 2 ounces if I could find the right widths. Less fiberglass, less epoxy.

How much epoxy for a teardrop? Can't say but I'd guess three gallons. You might ask KC over on his Poet Creek Express build. He'd have a better idea.

If I were going to fiberglass a teardrop, I'd do it the same way Steve Fredricks does it in his Teardrop Shop Manual and lay up the walls while they are flat during the build process, fiberglass the roof after assembly, and finish off with bias tape along the seams.

Lot of videos on glassing cedar strip canoes on Youtube.

Tony

p.s.

Do different resins have UV rating like regular human sunblock?

Nope. Some of them have a UV-resistant additive. How well they work I don't know, but with stripper canoes, you keep adding coats of spar varnish as it gets sun damaged instead of sanding into the epoxy/fiberglass layer and causing grief.

[stevef22]

Thank you Tony for information! I now know using coats of varnish on outside is the norm - yearly to protect from UV. I also purchased Steve's manual ( Great name ) Reading it and learning so much.

Also took a look over at KC's build.
KC over on his Poet Creek Express build
http://tnttt.com/viewtopic.php?f=55&t=48630&start=4035 Will check in with him on fiberglass knowledge.


Thanks again, this is giving me a great head start on glassing info.

[stevef22]

Chuck with Duck Works also suggests putting varnish on outside of epoxy/fiberglass.

---------------------------------------- Reply from Chuck ---------------------------------------
Hi, Steve,
Not only texas but only an hour away from you in the hill country. We are just north of Kerrville.

Our DWX epoxy has two UV inhibitors – it is also very slow which is nice in the Texas heat.
http://www.duckworksbbs.com/supplies/ep ... /index.htm

We offer a number of weights and types of fiberglass:
http://www.duckworksbbs.com/supplies/cloth/cloth.htm

While this epoxy is UV resistant, we do not recommend it as a final coat. Varnish is much easier to use when you are looking for a bright, smooth finish. Epoxy is needed to laminate fiberglass, though.

Let me know if you have any questions.
Chuck

---------------------------------------- End Reply from Chuck ---------------------------------------


Thanks so much for all the help. Wait, I have to build the thing first before I start glassing.

Will keep everyone posted on progress.

[tony.latham]

I also purchased Steve's manual ( Great name ) Reading it and learning so much.

I swear by that thing. It was bible during my first build and was a great source on #2 & #3.

I'll be anxious to watch your build progress.



Tony

[stevef22]

Sweet drops!

Will keep you posted. Probably going to start a blog. : )

[Rick Tyler]

The boat building forum at http://forums.bateau2.com/ is strictly a composite/plywood/glass/epoxy group. There is a lot of expertise there, to go along with the experts here. The forum is really old (I joined in 2001), and is very expert.

My 2 cents:

I would use 6-ounce glass. It's easy to work with, not too expensive, and heavy enough to provide some wear and impact resistance. If you are using the glass to hold your trailer together, and not just a wear layer, I would suggest heavier material on the joints, like 6" wide 9-10 ounce, or even 6" wide 12-ounce 45x45 biaxial. (I have to remember that this isn't a boat, and if something fails it's unlikely anyone will drown...)

Everyone seems to have their favorite epoxy, and all of them will need UV screens (paint, varnish) of some kind. My personal favorite is System Three SilverTip. It's not cheap, but it is SO easy to work with, and has very low amine content which makes it less likely to trigger allergies. The only epoxy I've used that I really didn't like was Interlux, but unless you are buying from a marine supply company you probably won't come across that.

If you want to explore what is really possible with this technology, take a look at this TT from Chesapeake Light Craft: http://www.clcboats.com/shop/boats/deve ... ailer.html

[stevef22]

Thank you Rick for feedback and information. I have seen Chesapeake Light Craft before on google and thought it was awesome. Going to head over to other forum and dig around as well.

Thank you,

[Juneaudave]

Welcome!!! I have a couple thoughts....

Epoxy and cloth....I've used West, MAS and RAKA over the years and any of those would work well. I typically buy the slow hardener for clearcoating so I don't have to rush. For cloth on a tear, I like the RAKA 4 oz plain weave. They have good customer service, its cheap and they used to carry 4 oz in a 72 in width (I only saw 60 inch when I checked). I dont think you need 6 oz for strength, and if you go lighter than 4 oz, it gets pretty tender for handling (ie it will snag very easily as you lay it out). Dont rely on my estimate, but I'm guessing epoxy (1 1/2 gallon), cloth, pumps, brushes, rollers, mixing cups and sticks, etc at about $200.

For UV protection, nothing beats a good quality marine spar varnish with periodic maintenance. Having said that, on my tear I shot it down with three layers of auto clear coat. That has worked very well for over 6 years on areas where there is cloth. On the sides of my trailer, I did not use cloth, and the clear coat was too brittle for the movement of the wood. Good spar, or auto clear coat, might cost as much as the epoxy....but I would guess $150 by the time your finished laying on coats and sanding between. Again...dont relyu on my best guess estimate...

Hope that helps!!!

[tony.latham]

Welcome!!! I have a couple thoughts....

Epoxy and cloth....I've used West, MAS and RAKA over the years and any of those would work well. I typically buy the slow hardener for clearcoating so I don't have to rush. For cloth on a tear, I like the RAKA 4 oz plain weave. They have good customer service, its cheap and they used to carry 4 oz in a 72 in width (I only saw 60 inch when I checked). I dont think you need 6 oz for strength, and if you go lighter than 4 oz, it gets pretty tender for handling (ie it will snag very easily as you lay it out). Dont rely on my estimate, but I'm guessing epoxy (1 1/2 gallon), cloth, pumps, brushes, rollers, mixing cups and sticks, etc at about $200.

For UV protection, nothing beats a good quality marine spar varnish with periodic maintenance. Having said that, on my tear I shot it down with three layers of auto clear coat. That has worked very well for over 6 years on areas where there is cloth. On the sides of my trailer, I did not use cloth, and the clear coat was too brittle for the movement of the wood. Good spar, or auto clear coat, might cost as much as the epoxy....but I would guess $150 by the time your finished laying on coats and sanding between. Again...dont relyu on my best guess estimate...

Hope that helps!!!

Dave:

Your closing argument –– with that photo–– wins hands down. At least for me. (Interesting on the clear coat on the fiberglass but not on the un-glassed wood.)

Tony

[KCStudly]

I have no experience using epoxy for the woodie look, but if you select West System they have a special "clear" 207 hardener that supposedly does not give the slight amber tint and does not blush or cloud up in the presence of humidity.

Follow the kayak builders advice: let your cloth drape over for a day or 3 (it will relax and help you pull out any wrinkles); avoid piecing plies together or lapping, a single layer of glass will look much better when draped and pulled in one piece; mix carefully to avoid introducing bubbles; only layup in a warm environment with falling temperature (better absorption with less chance of the wood out gassing bubbles); get rid of any loose strands (they will wad up into little balls as you squeegee and can create cloudy spots); don't over do it squeegeeing (you can pull wrinkles into the cloth, use a cut down chip brush to stipple... just be sure to pluck out any loose brush hairs); etc.

I will say that I have been terrible at doing long layup sessions. Some people swear that you need to do your initial wet out, lay and wet the cloth, let that tack up good, and then start laying on the filler coats; tack up; coat; tack up; coat; etc. until you have filled the weave plus a couple of coats for sanding... all in one marathon session. I have never had the block of time or staying power to do a long enough session to work that way, so I spend a lot of time washing and scrubbing amine blush, and scuffing in prep for the next operation. Plus I am at the mercy of the weather on my temperature control. Fortunately I don't have to worry about a lot of stuff because I am doing paint top coat. Also, I find it perfectly suitable to lay the cloth on dry and then wet out; we're not laminating large ply counts here, not building 200+mph boats or airplanes, and it gives so much more control over getting the cloth located how you want it with the strands all running as close to straight and true. Laying dry cloth into wet, or wet on wet w/o several helpers to stretch it out is really hard, in my experience.

On TPCE (64 wide x about 49 tall x 9ft-8in long, not including under floor), using two 6oz plies for added stiffness directly over foam, including the tongue box, I think I've gone through about 2-1/2 gallons so far with very little wasted (maybe its 3-1/2?), but I have yet to fill most areas of the weave. I plan to thicken the weave fill coat, which will use less wet than clear epoxy but still probably more than 4oz cloth would. Will use still more for a barrier coat over the sanded fill coats, before paint. So that is probably a lot more than what would be needed with a single 4oz ply. The sanded foam definitely soaks up more than the wood areas, so your experience will be different.

The 6oz cloth I have been using is listed as 60 wide, but with selvage is actually 61 wide, and runs $7-$8/yd at large marine supplier (Defender Marine). Using West System, I had been figuring about $100/gal total but it looks like the prices have gone up recently, $100/gal just for the resin and another $50 for hardener to do a gallon; except the 207 hardener costs more, $88 to do a gallon (different mix ration). So, yes, it is costing me every bit as much as an outer ply layer, aluminum, and trim would have, but w/o the trim and all of the fastener holes to be sealed and find ways to leak. I wanted the benefit a monolithic outer skin with rounded corners, and am "jambing out" the side doors and hatch seal edges.

[Mitchelkitman]

Maybe I'm crazy, but I just don't understand why it would be practical or desirable to build out of wood, and then use GRP as well - why not just build out of GRP (with no wood) and have no potential wood rot issues, a lot less weight , and (if built correctly) more strength as well. My (albeit small) 6ft x 4 ft (but 6ft 4 inch headroom) folding trailer only weighs 200kg all up.

[tony.latham]

Maybe I'm crazy, but I just don't understand why it would be practical or desirable to build out of wood, and then use GRP as well - why not just build out of GRP (with no wood)

Do you mean fiberglass/epoxy by "GRP?" I'm thinking that's a British term?

To answer your question, wood is a great construction material. I'm in a wooden house and it's not subject to rot because it's built using acceptable methods. Dave's woodie lives in a rainforest if I'm not mistaken. Properly constructed wooden boats or teardrops should live for lifetimes with little maintenance.

Wood is good!

Tony