Thrifty Alternatives ..Building Foam Campers

[KCStudly]

Here's a thought, immediately after glue up weigh the assembly on a digital scale.

When the assembly stops getting lighter the liquid is either done evaporating, or is trapped and can't get out. Then is the time to start cutting and see which one it is, dry or not.

Schmaybe?

[ghcoe]

I am curious how strong the Gripper surface is when dry. I know that you mentioned it could be sanded, but does it seem durable? Such as if you pressed your finger against it would it indent easily or spread out the force a bit first?

[GPW]

George , it’s just a primer , not fiberglass ... everything dents .... if you push hard enough ...

KC , Good idea ... but I have no digital scale ... But I have weighed green wood in the past making bows to see when it stabilizes (moisture content) with the relative humidity...

[GPW]

Just thought I’d mention this . For smoothing out fabric, old T-shirts, paper, etc. a ”fiberglass layup roller" works very well !!! It’s like a regular roller , but seemingly made into little disks strung together , so it won’t stick to the fabric/glue and pull it up as a flat roller would . The plastic ones are Cheap and using it as we do , lasts a long time ... It forces the air bubbles out and flattens the material for better adhesion, and a smoother finished surface.

You Ladies who are doing that brown paper bag style floor ... This would be Ideal for getting everything perfectly flat , no bubbles ... For Fiberglass hand layup work it’s almost mandatory ... The fiberglass guys know eh !!!

[Wobbly Wheels]

Hehe...yup...
Just to add - you can get them with different length and diameter rollers on them. For that I'd suggest a big one (1"dia) to make quicker work of big flat panels. Little ones like the pic are great for getting into tight corners.
Oh, and be diligent about cleaning them: when those groves get plugged up they're useless and almost impossible to clean out.

[Bogo]

Just thought I’d mention this . For smoothing out fabric, old T-shirts, paper, etc. a ”fiberglass layup roller" works very well !!! It’s like a regular roller , but seemingly made into little disks strung together , so it won’t stick to the fabric/glue and pull it up as a flat roller would . The plastic ones are Cheap and using it as we do , lasts a long time ... It forces the air bubbles out and flattens the material for better adhesion, and a smoother finished surface.

The disk structure is so it forces the fiberglass matting down through the resin, but doesn't push the resin away. This makes it easier to get the fiberglass fully wetted. It would do the same for any fabric/glue or fabric/paint composite.

[Wobbly Wheels]

Just figured I'd post this up since I don't think it's been tried yet...

I had some drop cloth left over from another project, so I banged up a frame for it and stapled it on.


Then I hit it with an old spray can of RV roof paint that was also a leftover.


First coat


I just got back from doing the second coat before the propellant gave out. When that dries I'll post the finish.

Because the roof paint soaks into the weave but is too thick to actually saturate the cloth, it seems like it might be effective to pre-paint the outside of the canvas with it, then paint the canvas onto the foam. I'll post a pic when it's dry, but the back side of the canvas is still dry so the Gripper or TB3 will still have plenty of bite on the cloth. If the dried paint is flexible enough, it might be easier to roll the paint onto bulk cloth (or precut pieces) from a roller tray and then apply the impregnated cloth over the foam after it dries.

If this piece works, I figure I'll stretch it over a couple laminated cedar bows and use it as a removable awning over the door. It may also be an economical alternative to big pieces of awning fabric (which ain't cheap !)

And BTW, it looks like TB3 isn't a solution to prevent polyester resins from eating the foam
Pics will be in my build thread in a bit.

[GPW]

W2 , don’t know why I never thought to mention this but we’ve been dealing with canvas for many years now , and raw canvas does require some preparation before it becomes useful (to paint on ) ... I’ve always stretched the canvas on a frame , vacuumed the surface to remove loose threads and dust ...then “sized” the canvas with a thin water soluble coating , either highly thinned Rabbit skin glue or Elmers white glue (not waterproof ) , a watery solution that soaks the fibers and stabilizes them as the solution dries ... Then apply the primer (Gesso)... and once the primer has dried and usually lightly sanded ... then the paint .
As it would apply to a trailer ... vacuuming the canvas is always a good idea , and was thinking of a sizing made of the Elmers non waterproof glue in a THIN mix with water.. the idea being , the initial sizing of the fabric prevents over stretching of the fabric over big areas, and also makes the canvas easy to trim , giving Clean non fraying edges... and if you want to stretch the canvas around a certain area , just a water misting with a spray bottle will de activate the Elmers so you can stretch the fabric more ... Later when you glue or paint the canvas down to the foam , the Elmers , as little of it as there is, just incorporates into the other adhesive... no problem ... Just a little sizing makes the canvas easier to work with ... JMHO

My concern with the roof spray is , is it porous enough to allow the adhesive under it to dry ... ? Would make a great awning though ...theoretically .... needs “testing” ...

[GPW]

Just another idea .. For small foam parts , with tricky rounded contours to cover, what about using a super stretchy fabric ... like common cheese cloth ... it stretches all kinds of ways ... and it’s cheap Once glued down , it would add a good bit of strength to the foam part and the weave could easily be filled with a thick primer and sanding ... sorta’ like poor mans' fiberglass...

[Wobbly Wheels]

As far as the adhesive drying under the roof paint, I figure that if Gripper will set up between a couple styrofoam meat trays, the paint has GOT to be more porous than that.

Thanks for the tips on sizing. Does it tend to make the paint sit on top of the canvas or can it still soak in ?
Cheesecloth sounds like a good idea to me. One could add as much fiber as needed for strength by building it up gradually, even for compound curves...like fiberglass matting.

[GPW]

meat trays ... True enough eh ?
The sizing only serves to remove/incorporate the fiber “fuzzies” , but should “melt “ into and become part of any other water based adhesives... The sizing itself is very thin , doesn’t even feel sticky like glue ... 1:10 glue to water should be more than enough ... just a stiffener , like spray starch ... and not even that much ...

[GPW]

OK, here’s one for you ... the plane guys are considering this as a skin , held on with "the Gripper” ... http://www.materialconcepts.com/store/p ... yvek-1443r

And they even have a fabric -like soft Tyvek too ... crumbs for thought ... This is pretty Tough stuff ...

[Jack B.]

So . . . Are the airplane guys using standard Tyvek? Or is it the a softer version they're using? I hadn't considered using it. but you're right. It is tough stuff. A couple decades ago I had a light windbreaker type jacket that was made of a Tyvek product. Talk about paper with an attitude. You could machine wash it and it lasted quite a long time for me. If the glue/paint/primer gets a good soak into/through the material if would definitely be the strong way to go.

I wonder how Tyvek would work for awnings or stretched over a frame and varnished. Not to mention the ability to draw or stencil designs and patterns onto it before coating with clear coatings. Lots less stretching than with cloth fabric I would think.

Dang. Now I have another excuse, I mean reason, to head off to the big box hardware store.

Jack

[GPW]

Jack , they’re just using the standard stuff mostly bits of old mailing envelopes ... for now ...

[GPW]

Starting to get some Gripper feedback from the plane guys testing .... it Works for them too ... And they also report it is easy to sand , doesn’t gum up the sandpaper ... Don’t think we ever got to that part as yet ...