Fiberglassing Tutorial

[Jimbo]

Can anyone recommend any good websites or books on fiberglassing? Friend is interested in fiberglassing rather than using sheets of aluminum.

[doug hodder]

For me....I've used West System www.westsystem.com they have a free brochure on materials and usage....Also try www.raka.com I know there are others out there and if in doubt about what you want to do...contact any of their technical guys....I've always gotten good results by doing that...It's not the easiest stuff...but the results are great....Also try "How to fiberglass boats" by Ken Hankinson gives you the up to date materials info on sheathing...covers both polyester resin and epoxies..fabric selection etc....available through BoatBuilders...and probably Wooden Boat magazine...I know it's for boats...but the techniques are the same....Doug

[Steve Frederick]

Check out Epoxyworks, West System's online Magazine. There are links to lots of technical stuff, as well as, inspiration.
As the project progresses, just post questions here. I, and others here, have a lot of experience. We are all happy to share it!

[Arne]

If you have never used it, try a small piece, like 1 foot square. First, don't put too much on, it is terrible to sand it off....

Fiberglas will chemically bond up to 24 hours after it is applied, mechanically after that..... So, I put a coat of resin on with a brush and squeege it, very thin coat. After that and it hardens up a bit, I put on the cloth and squeege a second coat of resin on to saturate the cloth, but the weave still shows through.... 3rd coat usually fills the weave.

Even if I brush it on, I always use a squeege to take off the excess and leave a nice smooth coat.....

Some very light sanding usually finishes it up, ready for finish, like spar varnish or painting.... Others with more experience than I can correct above or fill in the gaps... but I treat is like drywall compound, I can alway add more, but getting rid of excess after it dries/hardens is a real chore....

[asianflava]

I experimented on small projects first. I glassed the fins on one of my model rockets. I'm by no means an expert but it let me know what to expect. One suggestion, get the pre-metered pumps. They will save you a lot of measuring and mess.

[Jimbo]

It all looks like good info. Thanks, I'll post pictures when we try it. Yep, looks like I'm gonna be helping...

[Flonker]

Can anyone recommend any good websites or books on fiberglassing? Friend is interested in fiberglassing rather than using sheets of aluminum.

Something I've run into along the way:

http://www.rqriley.com/frp-foam.htm

It's a nifty lil tutorial on using foam and glass, which I'm thinking of building my trailer from. I figure it'll keep the weight down enough on a Midget/Widget/Squidget/Tidget to enable it to be towed behind a high mileage '85 Lancer 4-banger, aka, my daily driver. I'm seriously thinking of trying a more 'traditional' design first to gear up for the M/W/S/T, get my technique down pat, and so forth. I'm just wondering what kind of glue I'll need to glue the wooden spars to the foam panels...

[Joanne]

Can anyone recommend any good websites or books on fiberglassing? Friend is interested in fiberglassing rather than using sheets of aluminum.

I know just the place where you can learn fiberglassing! My teardrop! Although I've got most of it done I still have the rear hatch and the side doors to do. I also have to add a couple of additional coats of resin over the entire trailer, then lots of sanding before it's time to paint.

Of course it is quite a ways from Kentucky to Nevada for a lesson, but feel free to drop by anytime!

You might want to try your local library to start with. You can also try Amazon and look up fiberglass. West Marine has a selection of books on boat repair that usually cover fiberglass work.

Joanne

[Juneaudave]

This might be relevant...at least interesting...I'm planning on building stripper type "Woody" sides and paint the roof and hatch (to match the tow vehicle) over 4 oz glass. I contacted West Systems regarding painting, with the hope that I could put the primer and color coats on the roof, then shooting the whole shebang with clear coat. That would avoid the tedious spar varnish for UV protection and should put a pretty nice finish on. Here was the response (which I thought confirms my experience, at least with polys over glass)...

Dave,

As long as the 105/207 you use on your final coats over the wood are fully cured, washed, and sanded you shouldn't have any problems. There are certain coatings that do not dry if the epoxy hasn't fully cured or is mixed off ratio. If your shop is below 60-65°F, the epoxy will take longer to come to a final cure.

I would say to coat the entire project with 105/207 and allow it to cure. When you are certain the cure is adequate, wash with water and follow the paint manufacturer's surface prep for fiberglass. As long as your clear has a good UV resistance to protect the epoxy, there shouldn't be any problems there. Regardless of the information I have sent you here, its always a good idea to create a test panel with the exact products you are using in the environment you are using them in. The stress levels involved are much lower if you're troubleshooting why your test panel didn't turn out vs. your entire project.

This next section is taken directly from Westsystem.com - it gives a guideline for compatibility with certain types of paint.

Finish coatings

The function of a finish coating like paint or varnish over an epoxy barrier coat, is to decorate the surface and protect the epoxy from sunlight. In doing so, the finish coating extends the life of the epoxy moisture barrier, which, in turn provides a stable base that extends the life of the finish coating. Together the two form a protective system far more durable than either coating by itself.
Protection from sunlight is a primary consideration in the selection of a finish coating. Long term UV (ultraviolet) protection of the barrier coat depends on how well the finish coating itself resists UV and keeps its pigments, or its shield of UV filters on the surface of the epoxy barrier coat. A high gloss finish reflects a higher proportion of the light hitting the surface than a dull surface. All other thing being equal, a white (especially a glossy white) coating will last the longest.

Most types of coatings are compatible with epoxy. Thoroughly cured epoxy is an almost completely inert hard plastic. This means most paint solvents will not soften, swell or react with it. However, it is still a good idea to build a test panel to assure coating compatibility.

Coating types

Latex paints are compatible with epoxy and they do an adequate job of protecting the epoxy barrier from UV radiation. In many architectural applications latex paint may be the most suitable coating to use. Their durability is limited.

Alkyd finishes-enamel, alkyd enamel, marine enamel, acrylic enamel, alkyd modified epoxy, traditional varnish and spar varnish-offer ease of application, low cost, low toxicity, and easy availability. Their disadvantages are low UV resistance and low abrasion resistance.

One-part polyurethanes offer easy application, cleanup and better properties than alkyds. They are also more expensive and some may be incompatible with amine cure epoxy systems such as WEST SYSTEM epoxy, although 207 Hardener may offer better compatibility. Test first.

Epoxy paints are available in one-part and two-part versions. Two-part epoxies offer many characteristics similar to the higher performance polyurethanes. They are durable and chemical resistant, but offer limited UV protection compared to the linear polyurethanes.

Two-part linear polyurethane (LP) paints offer the most durable protection available. LP's are available as pigmented or clear coatings and offer excellent UV protection, gloss retention, abrasion resistance, plus compatibility with epoxy. However, compared to other types of coatings, they are expensive, require more skill to apply and present a greater health hazard, especially when sprayed.

Bottom paints are available in a variety of formulations. Most bottom paint systems are compatible with epoxy and can be applied directly over a prepared epoxy barrier coat. If you are unsure of compatibility or have curing or adhesion problems with a specific bottom paint, use only a primer recommended for that bottom paint over the barrier coat. Follow the recommendations given for preparation of fiberglass surfaces. Other paints, including marine LP's and primers, are not recommended for use below the waterline.

Primers are usually not needed to help a paint film bond to epoxy, although interfacing primers may be required with some specialized bottom paints and high-build primers are useful for hiding scratches or flaws in the substrate. If the instructions on your paint or varnish recommend a specially primed surface, follow the recommendations given for fiberglass preparation. Self-etching primers do not work well on an epoxy coating because of epoxy's chemical resistance.

Polyester gelcoat is a pigmented version of the resin used to build fiberglass boats and other products. Gelcoat is sprayed into a mold before the glass fabric and resin are applied to provide a smooth pre-finished surface when the part is removed from the mold. It is not often used as a post-production finish coating, but it can be applied over epoxy and is useful in some repair situations. Refer to 002-550 Fiberglass Boat Repair and Maintenance, published by Gougeon Brothers, for detailed information on patching gelcoat over an epoxy repair.



If you have any other questions, feel free to write me back. I am also curious to see a digital picture of the final outcome if thats possible.




For what it is worth...Juneaudave

[cracker39]

Can anyone recommend any good websites or books on fiberglassing? Friend is interested in fiberglassing rather than using sheets of aluminum.

Something I've run into along the way:

http://www.rqriley.com/frp-foam.htm

It's a nifty lil tutorial on using foam and glass, which I'm thinking of building my trailer from. I figure it'll keep the weight down enough on a Midget/Widget/Squidget/Tidget to enable it to be towed behind a high mileage '85 Lancer 4-banger, aka, my daily driver. I'm seriously thinking of trying a more 'traditional' design first to gear up for the M/W/S/T, get my technique down pat, and so forth. I'm just wondering what kind of glue I'll need to glue the wooden spars to the foam panels...

That tutorial states that they used 1"rigid urethane foam boardstock", but it looks like it bends pretty easily. I have a Mechanics Illustrated book packed away somewhere, that is about 30 years old. It has plans to build a sailboat with a foam material that bends easily when heated with heat gun. The rigid urethane foam boardstock in that article seems similar, but appears to bend without heating.

I like the idea of building with it. It would make the TTT a little lighter. However, I wonder how much trouble it would be to lay cloth on a verticle surface and get it to stay put? My glass work has been limited to one boat. With a cloth application on the outside, the resulting walls would be rigid enough by themselves without a lot of framing, but I'd still need "attach points" in the walls for spars, windows, door, bed/shelf/Air supports, etc, so I doubt that my framing would change much at all. I suppose the foam adhesives that come in standard "gun" tubes would work for adherring the foam to the wood.

[Arne]

I've give this a bit of thought.. if you look at the way we (Me) build, we throw a lot of extra, unnecessary wood, into the framing. When I built mine, I did not consider the foam part of the structure, but it is when faced on both sides with ply and glued. I put 1x6 pieces where 1x1 would have work IF I had given a lot more thought to design. Thinking about it, the only wood really necesary is where other wood has to be attached, so around the perimeter of the wall, bulkhead attachment, etc.....

[cracker39]

I've give this a bit of thought.. if you look at the way we (Me) build, we throw a lot of extra, unnecessary wood, into the framing. When I built mine, I did not consider the foam part of the structure, but it is when faced on both sides with ply and glued. I put 1x6 pieces where 1x1 would have work IF I had given a lot more thought to design. Thinking about it, the only wood really necesary is where other wood has to be attached, so around the perimeter of the wall, bulkhead attachment, etc.....

You are right. Most TDs need less framing than you put in. My TTT however, has lots of attach points for other wood. I have to attach the forward gally and portipotti cabinets, upper shelves front and back, two underbed storage areas, and a bed platform support rail on the walls from the storage/seat box forward on both sides. I intend to keep the side framing down to 3/4" 1 3/4" in most areas. Only in the back wall for A/C support and the roof for mounting the fan, will I need heavier framing pieces. I calculate that allowing a half inch for 3 saw cuts, a 1 x 8 (7.5" wide) will produce 4 pieces of 3/4" x 1 3/4". That won't take a lot of lumber to frame my TTT sides. Even the perimeter framing curves can be cut from 3/4" x 3". I just need to leave 1" for the foam and inside skin, plus another 3/4" to 1" to attach the side skin edges and corner molding.

I may try to find some of the eurothane foam and get some polyester resin and glass cloth and try a small test...maybe a box about a foot square. That would be large enough to get the feel of it and see how it finishes. That would also let me give me an idea on how much work would be involved overall to do the TTT with it. Until now, I've resisted the idea of glassing over wood due to the extra weght, but the foam without a wood skin would work out if I see I can do the job and get a good, smooth surface.

Another advantage to using the foam, is that you end up with a thicker wall surface which is better for mounting windows and doors, which are usually deeper than my wall would be using just plywood. And, with additional foam between the skins, in the framing, the inslulating properties are probably more than doubled. Can any one else think of reasons not to use the foam skin?

[Gaston]

I am building my TD with a 1/8" luan door skin inner wall, 1" thick wood frame, then 1" pink polyfoam insulation in the frame. Then 1" pink poly foam epoxied as a overall outer side and top, covered with 3 layers of fiberglass using epoxy resins. I am doing it this way because I want it light, and I wanted to be able to do some forming to the shape. Because of the cost of epoxy it ain't going to be cheap If you want to "glass" your tear but are concerned glassing vertical surfaces, then glass the side panels flat before you install to the floor and bond together when you glass the roof.

[Jimbo]

OK, I've been doing some looking into this for myself as it's pretty interesting. If I understand this correctly, I could build the walls out of foam and glass over them. How many layers of mat should be used? Would this really work? If so, it seems like it would make for a very light weight project.

[Joanne]

OK, I've been doing some looking into this for myself as it's pretty interesting. If I understand this correctly, I could build the walls out of foam and glass over them. How many layers of mat should be used? Would this really work? If so, it seems like it would make for a very light weight project.

Hi Jimbo,

If you are concerned about weight, your approach will achieve that. I believe that the down side would be cost and labor. I've read some boating websites where they have built panels similar to the ones that you are thinking about, although they commonly bond their interior paneling to both sides so they can build interior walls or doors.

In order to build a well bonded panel, many of these builders use a vacuum bag technique to apply even pressure across the entire panel and ensure that there is no excess resin left to add weight. That may be an overkill for what you are planning, but you might want to look into the process anyway. The other issue is the type of resin you decide to use. Polyester resin is much cheaper but is incompatible with many types of foam (it dissolves it). Epoxy is less of a problem in this area but is more expensive. If you want to try this method, I would suggest that you make some test panels to verify that your technique works as you plan and that the panels have the strength you need. (try various laminate schedules) As other have stated, don't forget to include mounting points for cabinets and such.

There is a good article on the West System website that talks about attachment points when using high density urethane foam.

http://www.epoxyworks.com/22/fasteners.html

Although I used a more traditional plywood/epoxy technique, I would love to see someone build a foam/glass trailer.

Good luck!
Joanne