Wes' teardrop - Fiberglass finished Bondo started - Page 9

[WesGrimes]

I know what you mean about the dips and bumps in the roof. They are all over the place right now. The challenge is not allowing the drip rail to disappear. I plan to build the roof up as needed to try and smooth the thing out. I will most likely then have to build up my radius to maintain the lip. It is going to be a challenge to say the least...

I will no more about how I am going to overcome this problem when I am finished.

Thanks,
Wes

[starleen2]

sometime ago I watched an episode of "This Old Hose" in which they were reproducing a section of plaster moulding using something similar to what you constructed in SketchUp. The dragged the profile cutout in the wet plaster a couple of time until the contour emerged. Seems like the same thing could work here. I used the same tech with body filler and cardboard to get a fender radius without much sanding afterwards

[WesGrimes]

sometime ago I watched an episode of "This Old Hose" in which they were reproducing a section of plaster moulding using something similar to what you constructed in SketchUp. The dragged the profile cutout in the wet plaster a couple of time until the contour emerged. Seems like the same thing could work here. I used the same tech with body filler and cardboard to get a fender radius without much sanding afterwards

That's kind of what I am thinking. If I make sure that the top and side is where I want them, i can drag out the radius in wet compound, and then sand it out.

Thanks,
Wes

[cappy208]

i wasnt clear about the tubes: they are cut in half lengthwise, so they form a u shape. you lay up the glass right over them and leave them there.

[WesGrimes]

i wasnt clear about the tubes: they are cut in half lengthwise, so they form a u shape. you lay up the glass right over them and leave them there.

This is going to be another challenge. I intend to have 2" walls. 1/8" outer shell, 1/8" inner wall and 1 3/4" insulation.

How to separate the skins, attach the insulation, attach the inner skin, are all up in the air.

A similar approach that I have been playing with is to use foam pipe wrap cut in half. This would not have the same cavity for wires, but would make excellent "stringers".

I can use a vinyl foam core and vacuum bag it. I could cut channels in the core material for wire channels. This is WAY overkill, and pretty expensive. The thing would be ready to set sail on the Atlantic though.

I am going to experiment with an I-Beam type design. If I cut strips of cardboard 1 3/4" wide and layup glass tape on both sides of it, I could then attach some really thin and light aluminum channel to it. The advantage here is that I will then have a surface to screw the inner shell to. The voids between the I-Beam "stringers" could then be filled with foam board adhered with 3M spray adhesive. This would be cheap and easy, but not as strong (or heavy) as the core option.

I think I am overbuilding this thing. Good news is the plug and mold design are not affected by these decisions, so I am waiting to finalize the plan.

You mentioned the lap joint with the roof/sides. I have some ideas on this, but it is another to be determined item. I had not planned on having the joint in the first place, so I am retrofitting it into my design.

I think what I will do is create the roof and trunk molds and pop a finished part out of them. Then I will sand and tape over the rough side of the finished part's radius. I will then layup some glass there to form the lip of my wall's plug. I will then attach those flanges to the wall plug. This will provide me with a 3" lap joint that I will adhere with A/B epoxy. I think that the lap joint will be quite strong when it is finished. Probably stronger than the flat spans.

Thanks,
Wes

[Prem]

Wes and other fiberglass pros,

Have you ever seen a Mexican fishing PONGA (skiff)?

All the flat parts are plywood covered with cloth and/or roving and polyester resin. The rounded parts appear to be either lots of roving or chopper sprayed. Of course they do all this in factories with molds, but there is still a considerable amount of ply and some wood strips in each ponga.

Seems to me that one could do a one-off the opposite way: build the flat and simple curve parts of the trailer body glued and screwed and then chopper the rounded parts with a compound curve backing (PU foam) with mold release on it, give it a sanding and finish with a layer of cloth and resin top coat.

There's also the chine method that no one here has used/posted...yet. One could pre-fab the chines out of roving and resin, stitch to shape with copper wire and then put a layer of roving and cloth on both the inside and outside.


I'm contemplating paper or cloth mache over formed wire mesh, dried, sanded, then a covering inside and out of resin and fiberglass. Could be next summer's trailer project called "Area 52." 5' x 10' x 5'



Prem

[angib]

Even if you use a section template like the sketch, you will still need to sand the surface smooth afterwards. Anything with a flat base will just sand flat spots into the corner and you have to start filling again. So you need a sander that will fit the corner shape. That rules out any power sander - this will be a hand-only job.

I suggest you search for bendy plastic pipe about 1" or 1-1/2" in diameter - 2" or 3" would be much better for sanding but will be too stiff to fit the lengthways curve of the corner. The length needed will be around 24". Use spray glue to bond sandpaper to the tube - you could try to hold the sandpaper to the tube with your fingers, but they'll be hurting enough already.....

The tube needs to be held running front to back. Your hands will need to be near the ends to maintain the curve that fits the shape of the trailer. And now move the sanding tube at 45 degrees so that you travel both, say, forwards and up over the corner at the same time.

Stopping the sanding tube from rotating will take all the strength of your fingers - if you can get someone to work this with you (when a 36" long tube might be better), the twisting problem will be much less, though you do have to synchronise your hand movements - this requires either song or obscene comments, either of which make this tedious job run more easily....

Andrew

[cappy208]

How is it going Wes?

Curiosity is killing the cat!

Your walls may be done easier by making a laminate of existing panels.

Look at this for the exterior panel: http://www.tchweb.com/tchstore/category/fiberglass-laminate/s0/510---FRP-Laminate-Panels.html

and 1/8th inch birch plywood for the interior.

The fiberglass laminated plywood is 5/16" and the 1/8" plywood would make the walls thickness dependent on the insulation. But this is already available on the market.

The R value of a solid piece of 3/4" plywood is 1. I would think a foam, ply laminate could be made easier and thinner and still keep the r value up there? The fiberglass laminated plywood is available in 3/4" too.

[grizz]

WOW !!!!

Impressive build this.

I love different approaches to stuff.

[WesGrimes]

Thanks Grizz

Cappy,
I may look into something like that. The local big box stores sell a similar product. I am thinking that I will be molding drip rails and such into the door opening, so I am not sure it would be worth it...

I have not made much of any progress over the last month. I ran out of funding for the project after the frame build, and ran out of materials when I ran out of money...

New month, new paycheck, new materials.
Got some more foam in this week and have filled in the passenger side radius with the foam. I still have to shape it after it finishes hardening. Then it is time to put some CSM and resin over the whole thing. I am really looking forward to fairing this part and being past this foam stage.
Here are some pics to keep the picture mongers at bay



I also mounted the side rail back on the drivers side:

[starleen2]

Here are some pics to keep the picture mongers at bay

It only last for a little while - then we're back for more

[starleen2]

Hey Wes, any further progress?

[Changer]

Any chance to come see this thing?

THIS type of building, I know I can do!

(It can't be harder than resin casting, just on a giant scale, right?)

[doug hodder]

I dunno what happened, but Wes has cleaned out his album. Anyone know? Doug

[Micro469]

I came back to see the progress too, Sure hope everything's all right.....