Van's and Fiberglass

[RV7Guy]

I'd like to preface the following rant with the fact that I actually enjoy fiberglass work and am not a fiberglass hater like many. I have considerable experience working with a variety of materials including vacuum bagging with glass and carbon. My plane is an RV7 so your kitglass may vary slightly. I molded all of my tail glass into the various parts. These can be seen at Brad Olivers site at www.rv7factory.com under the tips section. Also understand, for me, all fiberglass work must be perfect and I didn't stop until it was.

Facts- Van's uses to OEM's for their glass. The cowl and wheelpants are made from an Epoxy glass lay up. The wingtips and tail glass are polyester resin with significant gel coating.

The gel coated polyester parts are relatively easy to work with although you must understand that there are many voids in the glass that are covered by the gel coat. These need to be discovered and filled or they will manifest themselves later.

My real frustration came with the cowl. As I began my prep by liberally washing the cowl with acetone and sanding with 150 grit paper, I noticed that much of the cowl had voids in the areas of the honeycomb structure. Voids are simply a lack epoxy to fill the weave or structure.

I sprayed a coat of Feather fill primer on the cowl to see how extensive the problem was. The primer really brings out the problems and it was much worse than I suspected. My first thought based on my experience, was that this was a very simple fix by adding more epoxy to the layup during manufacturing.

There are many techniques to fill the inadequate layup. Some use epoxy and microfiller squeegeed in. Others use Rage or other types of fillers. I used a few different techniques to see what worked best.

When I thought I was really close to being done with the filling, I sprayed on 3 relatively heavy coats of Feather Fill primer on the cowl. I was still shocked at how much was still unfilled!!! I now filled the remainder of voids by "fingerpainting" Feather Fill into the voids.

This is when I realized, "okay, I like working with this stuff and I'm totally frustrated. I can imagine what the average builder is going through." I wrote and email to Van's asking why the cowl quality was so inconsistent with the quality of the rest of the kit and why to different types of glass stuff was being used. Regarding the cowl I mentioned that the fix was rather simple.

I received an email back from Van's that said if they had to add more epoxy the price would go up. Regarding the polyester glass stuff, he said that polyester was cheaper and easier for the end user to work with. So where is the logic? The cowl pieces are the biggest glass pieces in the kit and the most visible, so why are they the toughest to work with?

I replied and said that Van's was probably the major income source for these OEM's. (may or may not be accurate) If Van himself called and said, "the glass quality is not to my standards, please fix," I'll bet the cowl would be improved.

I also noted in my reply that the fix,(in my estimation) would only require 6-8 oz of additional epoxy to fix the problem. Our retail price of epoxy would put this at roughly $1 per ounce. At wholesale, (manufacturers price) it would only be about 1/2 to 2/3's of that. So, $6-8 retail for higher quality cowl, I'm in!!!

Finally, I said that if the kit prices were raised a nominal amount for improved glass work, sales would not suffer. I don't believe anyone would make the decision to not buy based on an increase of a few dollars. This is especially true when you realize it is going to cost you more than that to fill the cowl when you get to that point.

Now where everyone can step in and affect change for future builders, the reply from Van's also included the statement, "we don't get that many complaints on the fiberglass."

For those who have completed their planes or are in the process of working on the glass, simply send an email to Van's to provide a few thoughts on the quality.

Please understand that I'm not complaining about the overall kit quality. The past couple of years have been some of the most rewarding of my life and I love my 7. I will be traveling the Country proudly flying the Van's flag and preaching the benefits of the RV line to who ever will listen.

My only purpose to make Van's aware that the glass work is probably the lowest quality point of the kit. I believe they don't receive more complaints is that the glass is usually at the end of the project. We get caught up in the process and when done we forget the undesireable things.

Lets help out those behind us in the process.

[jcoloccia]

re: why epoxy and not polyester on the cowl

I believe it comes down to the epoxy is a better choice for large structures because it's structural properties are far superior to polyester. I believe you'd probably end up with a lighter layup with epoxy than polyester since you can have a thinner part.

Pinholes are a PITA. I've had some success in the past using this technique, but I've always been hesitant to mention it here because someone's gonna warp their cowl, or otherwise make a huge mess.

The whole problem is getting something thin enough to flow into the holes, right? Okay, well there's a way to make epoxy practically water thin....heat it up. I use a hair dryer, sometimes a heat gun, to heat up the epoxy after I've squeeged it on. The little bits that's are just floating over the pinholes will flow right in. Problem solved....works for me, anyhow. It doesn't need a lot of heat!!! Just a little bit will do it. Certainly cool enough to touch. Think nice warm bath water.

disclaimer: If you use this technique and melt/warp your cowl, cause the epoxy to flash cure, cause a fire, etc it's you're own darn fault. I'm not recomending this...it's just how I've always done it.

edit: an added benifit of this is that it will cause the epoxy to cure faster AND will tend to make the epoxy more brittle. Normally, this isn't something you want, but in this case it will sand better. Wear a mask because if you overheat it, it can smoke and give off nasty fumes.

[rv8ch]

Originally Posted by RV7Guy

Now where everyone can step in and affect change for future builders, the reply from Van's also included the statement, "we don't get that many complaints on the fiberglass."

You've gotta be kidding!

First, I'm really surprised that Van's is not aware that just about everyone moans about filling the zillions of pinholes in the cowl. How many hours of work is that for the typical builder? A lot!

Second, I'm even more surprised that this is something that can be made better at the factory. I was always under the impression that it was not possible to do it better. Of course, I just assumed this - I don't know anything about the manufacturing process for these cowls. A buddy of mine who has built two RV4s saw my cowl and was shocked at how much better it was than the ones he received from Van's for his RV4, so they are making progress.

I personally would pay extra money to have all the fiberglass done better. In fact, I bought upper and lower fairings, premade. That was at least a couple of hundred dollars.

I appreciate Van's quest to keep things as inexpensive as possible, but I think they are leaving a lot of money on the table. They could have a "rough" cowl and a "finished" cowl, and charge more. One phone call to the supplier, and an extra part number. More profit. Once they realize that everyone buys the better cowl, they can drop the other one. I think they should hook up with Sam James - his cowl is very cool.

Anyway, thanks for the "rant"!

[rv6ejguy]

The pinhole epidemic on my 6A glass added another 60 hours to my overall painting bill not to mention the previous 80 that I already did on the parts before I gave up and handed them over to the professional. We found the best solution was to warm up the parts carefully with a heat gun and ROLL thick primer over the whole thing. As the part cools, the air inside the pockets contracts, pulling the primer into the void. A couple coats and you are ready to spray over top.

Not fun or cheap.

I absolutely agree, I'd pay another $1000 to have glass actually ready to paint from Van's and this was a lame excuse. The rest of the kits are so nice!

[ge9a]

I haven't started any of my fiberglass yet, but I've been to Wally's class, and I read all I can. I'm still leary of starting, but I know I'm going to start soon. I doubt it will be as bad as I suspect once I focus on it, just like many other parts of this kit that I have tackled so far.

That said, I'd say most builders don't complain because we don't know anything about fiberglass until we delve into it for this project. At least that's my experience, and I doubt I'm alone on that thought. We don't know that it can (and maybe should?) be better! We don't have the experience to talk to Van's intelligently about it. We must leave that to others that are "in the business." From what I have heard, I'd be happy to pay some addition money for 'better' components, if it saves me a headache or two and some time.

Greg

[rvbuilder2002]

Originally Posted by RV7Guy

I have considerable experience working with a variety of materials including vacuum bagging with glass and carbon.

I guess this is your first exposure to a "prepreg" glass part. It was not made with a wet layup.
The cowls are made with glass cloth that is woven from glass fibers that are precoated with a small amount of heat activated epoxy resin. All of the layup layers are fitted into the mold, vacume bagged, and then put into an oven with a vacume applied. The amount of resin is not adjustable. Infact to have a strong but still very light part, the resin needs to be kept to a minimum. This is why prepreg parts are desirable.

If you where building a composite aircraft kit from one of the companies that use prepreg layups for the entire airframe (the now out of production Giles kits are one that comes to mind) you would be dealing with this on the entire exterior surface of the airplane.

I use Polyfiber "Smooth Prime" on all prepreg parts. I thin it slightly with water and roll on four or five coats with a foam roller. The documation says you can spray it but I never do. It sands so easily that it doesn't matter if the surface finish is realy smooth. After sanding with 150 then 220, spray finish primer and paint. Done.

[gbrasch]

How about we e mail this link of posts to Van's, maybe get some more comments in here before we do. I personally am a fiberglass dummie and am not looking forward to this work, especially being friends with Darwin (OK, I admit it) and knowing what he and others have gone through.......

[briand]

Originally Posted by rvbuilder2002

I use Polyfiber "Smooth Prime" on all prepreg parts. I thin it slightly with water and roll on four or five coats with a foam roller. The documation says you can spray it but I never do. It sands so easily that it doesn't matter if the surface finish is realy smooth. After sanding with 150 then 220, spray finish primer and paint. Done.

Maybe I'm missing something but I can't seem to find the "smooth prime", it looks like their products are mostly for fabric coating, could you help with a part # or something?


http://www.aircraftspruce.com/menus/cs/polyfiber.html

[RV7Guy]

Originally Posted by rvbuilder2002

I guess this is your first exposure to a "prepreg" glass part. It was not made with a wet layup.
The cowls are made with glass cloth that is woven from glass fibers that are precoated with a small amount of heat activated epoxy resin. Done.

No, I worked with it before. This is the worst example of it though. My friend just finished a Lancair Legacy and it wasn't nearly this bad.

Since the part is bagged the mold could have epoxy brushed in before the vacuum is applied.

There are ways to make the cowl better without adding much time or materials. This appears to be a cost savings measure.

If the effort is to make it light, the effort is somewhat being wasted on all the filler necessary to make it right.

[AntiGravity]

I for one would welcome better quality with less finishing required. I hate fibreglass and it hates me; anything I can do to ease the pain I will, even if it means buying non-Vans, and even if at higher cost (such as Holy Cowl; though I haven't compared pricing on that yet). I'm several years away from needing to worry about it, but enough builders tell Vans they'd like better quality then maybe when it comes my turn it'll be sorted. Please, if not for yourself, do it for me!!