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-   -   Nest Caravans Building a new FG trailer, step by step (https://www.fiberglassrv.com/forums/f51/nest-caravans-building-a-new-fg-trailer-step-by-step-63317.html)

Robert Johans 10-03-2014 03:04 PM

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Because the floor of the Nest carries the weight/load in lieu of a steel frame, extra reinforcement is required.

After a couple layers of FG cloth and/or matt is laid down, rigid foam is brought into position. This then is also covered with more layers of material. Ultimately, we will have a floor about 2" thick.

Robert Johans 10-03-2014 03:19 PM

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After all of the FG layers are in place, everything gets covered with "peel" cloth. This provides a barrier between the FG layers and the plastic infusion "bag," making removal of the bag and infusion tubes easy.

The bag is in fact a large sheet of plastic that is ultimately completely sealed along the perimeter of the mold. This plastic is cut and/or manipulated as necessary to follow the basic form of the mold.

But before the bag can be sealed, vacuum and resin infusion lines are laid into position throughout the mold.

Robert Johans 10-03-2014 03:35 PM

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Infusion technology uses a vacuum to pull the resin through supply lines inside the controlled environment of the bagged and sealed mold.

Given that this was our first attempt, and the unknowns associated with a mold of this size and detail, many feed lines were introduced into the bag to ensure a good "pull" and a full wetting of all of the FG layers within.

About 22PSI of vacuum was maintained for about an hour to ensure that all the air within the bag was removed before the introduction of our resin.

stevebaz 10-03-2014 03:48 PM

Wow your trailers wont have that new polyester resin smell. Looking good. Nothing like sealing a large vacuum bag. I wonder if any other makers are using epoxy's?

Robert Johans 10-03-2014 04:11 PM

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Catalyst is added to the resin and the mixture is then sucked into mold. The flow of resin is introduced in stages, allowing the bottom of the mold to fully wet first before pulling up the sides. At the appropriate time, other supply lines are opened to aid in the flow up to the top edge.

You can see the pinkish resin as it is being pulled through the FG layers. The constant vacuum ensures that all layers are completely infused with resin.

Each shell took about 12 gallons of resin.

Robert Johans 10-03-2014 04:26 PM

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About an hour after the resin has been sucked through the entire mold it begins to gel. Two hours later, the FG layers are fully infused, and the resin is cured, hard and dry. All of the tubes and plastic bag material are then pulled away.

We rolled the mold assembly outdoors and flipped it over... The newly infused part slipped from its hold and two men eased it to the ground.

Our new baby! About 13.5' long and 250lbs. Woohoo!

Robert Johans 10-03-2014 04:31 PM

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Having learned much from the experience with the top, the infusion process went even more smoothly on the lower shell.

Robert Johans 10-03-2014 04:52 PM

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Admittedly, these first units are not perfect. We learned a lot about the process and discovered some errors along the way.

With the parts now out of the molds we can see some problem areas within the molds themselves that need correcting. Some fine-tuning will be necessary before I am completely satisfied with the results.

Nevertheless, the shells look awesome. I am extremely pleased with the decisions we've made so far towards delivering an outstanding product.

These shells will be moved back into the fabricator's shop for edge trimming, sanding of some rough spots inside, and then a thorough, thorough inspection. We'll build and attach the front towing delta, as well as mount the axle/wheel/tire assembly to the lower shell.

Concurrently, the rear cap, door, wheel flares, and nosecone will be infused. With luck we should have all major FG parts made by the end of next week. Then comes assembly of the complete body.

Stay tuned.

KevinPete 10-03-2014 08:59 PM

Absolutely beautiful! Congratulations!

Ian G. 10-03-2014 09:57 PM

CONGRATULATIONS Robert, Your write-up is excellent and your trailer is looking awesome,

Donna D. 10-04-2014 06:49 AM

Oh WOW. Impressive!

Frederick L. Simson 10-04-2014 09:16 AM

Quote:

Originally Posted by Robert Johans (Post 485071)
Nest will instead feature the design-award winning Thetford "Curve" porta-potty, and a gray water external tote.

That's the same decision I made for my Compact Jr. rebuild!
I'm using a Barker Low Silhouette "Tent Camper" Tote. I'm making a cradle just forward of my axle for it to ride under the floor, as if it were a regular holding tank. To me it's the best of both worlds.

D White 10-04-2014 09:25 AM

This is why I love fiberglass. Is there any question, now, about why things cost what they do?..This is first rate

Carol H 10-04-2014 10:46 AM

Wow - what a lot of work! But it looks great!

Robert Johans 10-04-2014 01:25 PM

As you can see, infusion is a very laborious and expensive process. As it pencils now, easily two-thirds of our production costs lie just within the manufacture of our shell bodies and FG components. Perhaps this is why no other American FG trailer builder has yet embraced infusion technology.

As mentioned earlier, the ratio of FG to resin within traditional chopper gun production is about 35% FG to 65% resin. This not only adds brittleness to the product, but nearly doubles its weight, as compared to the infusion process. Toss into the resin (as is often done as a cost-cutting measure) talc or some other inert medium, and the overall strength is further diminished. And, when considering environmental and health-safety issues, the airborne chopper gun option is at minimum, dubious.

Our fabricator estimates the weight of an infused Nest shell mounted to our axle/wheel/tire assembly and front towing delta to be less than 900lbs. Even if we add another 1000lbs. to the interior, Nest could very well be the lightest 17' travel trailer in the industry. Less weight, better fuel economy any mid-size SUV, cross-over or light-duty truck can pull one.

Except for cost, old school chopper gun methodology simply pales when compared to the many benefits produced by modern infusion technology. And we at Nest are committed to producing a compact travel trailer of the highest quality. We're keeping our fingers crossed that some segment of the marketplace will also buy into that philosophy.

Ken C 10-04-2014 02:02 PM

I think snoozy does Vacuum Infusion technique
https://www.fiberglassrv.com/forums/f...tml#post347456

"This camper was built using a vacuum bag infusing process, this process
removes all air from the fiberglass before resin is introduced. Your
camper and all that follow will be built using what is called a "counter
mold" or Light RTM process. This uses what is essentially a second mold in
place of the bag. The "counter mold" will give us the same gloss and
texture as the exterior with the same color (a light tan color). It is an
in depth process that I will explain more completely if you are interested."

https://www.fiberglassrv.com/forums/f...tml#post242123

honda03842 10-04-2014 02:12 PM

Trailer Weight
 
Quote:

Originally Posted by Robert Johans (Post 485746)

As mentioned earlier, the ratio of FG to resin within traditional chopper gun production is about 35% FG to 65% resin. This not only adds brittleness to the product, but nearly doubles its weight, as compared to the infusion process. Toss into the resin (as is often done as a cost-cutting measure) talc or some other inert medium, and the overall strength is further diminished. And, when considering environmental and health-safety issues, the airborne chopper gun option is at minimum, dubious.

Our fabricator estimates the weight of an infused Nest shell — mounted to our axle/wheel/tire assembly and front towing delta — to be less than 900lbs. Even if we add another 1000lbs. to the interior, Nest could very well be the lightest 17' travel trailer in the industry. Less weight, better fuel economy — any mid-size SUV, cross-over or light-duty truck can pull one.

Robert,
I absolutely love the thread but wondered about the above statement.

This sort of Suggests that the empty shell of a Scamp 16 weighs 1800 pounds on it's frame. Is this true?

Mike Magee 10-04-2014 02:33 PM

I believe the empy Snoozy shell on its frame and axle is about 1200 lb IIRC; if so, you've knocked off about 25% of that weight. I think the added shell strength and reduced brittleness will be a more important factor, though.

Robert Johans 10-04-2014 02:35 PM

Nope, not saying that, Norm. But, when comparing two equally sized forms (L x W x D), chopper gun produces a unit that is twice as heavy as the infused. Or so I am told by the materials rep. I have no idea what the Scamp shells weigh. I would be curious to learn, though.


Sent from my iPad using Fiberglass RV

Robert Johans 10-04-2014 03:15 PM

Thank you, Ken, for alerting/correcting me as to LilSnoozy's infusion manufacturing techniques. (Also, thanks for that link.) Apologies for the mistake. Looks like they should get full credit for leading the way in our industry. Congrats!

Mike, not sure if we can fairly compare the weight of Lil Snoozy to the Nest. I believe the total dimensional area of our shell (including the nosecone storage box) is greater than theirs. We are also featuring larger wheels, tires and brake hubs. But honestly, we won't really know the weight of a Nest until it is completely built and accurately weighed. Hopefully, I won't have to return to this forum, hat in hand, begging forgiveness for understating the numbers on the scale!


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