Question about fiberglass work.

[NevadaBlue]

I’m removing a couple of windows from the fiberglass pickup topper that is the top half of my TTT. Yesterday, I removed the window shown below just to confirm that the fiberglass is FLAT around the window. It is.
I have flat fiberglass sheet, of about the same thickness as the topper, salvaged from a 5th wheel tub surround. I want to cut this to fit in the areas marked in yellow. The door will be between them.
I am thinking of how to hold the fiberglass panels in place while ‘glassing’ them into the wall. Would duct tape over the joint on one side hold it in place while I fiberglass the other side? Then remove the tape and fiberglass that side?

E7D30109-54BC-4DBE-89D2-8FA00DABEC1B.jpeg (76.57 KiB) Viewed 918 times

[tony.latham]

Ken:

Since it's flat, can you cut the glass so that it overlaps? And then epoxy it in place while it's held by temporary screws? After it's cured, you could fill the holes with thickened epoxy.



Tony

[NevadaBlue]

I could cut it to overlap, but I want the resulting wall to be flat, inside and out. I’ve thought of using ordinary clamps at the ends of the insert, that will be easy enough. And, maybe drilling a couple of holes, IN the match line between the wall and insert, and using small bolts and fender washers to hold all in place. Then, after the joint is set, I could fill the ‘blank’ spots.
I was just toying with a possibly easier way. I’ve never tried anything like this and it has been a LONG time since I have worked with fiberglass and resin.

[NevadaBlue]

I will be painting both inside and outside of the topper when complete, so grinding the edges of the join line thinner can be done, and then sanding and grinding should make a flat face.

[Pmullen503]

I'd use something more solid than tape. You don't want it to move while setting up. Better to have to fill some holes than to have to fix it or do it over if it moves.

[tony.latham]

I get it now.

I'd use something more solid than tape.

Could you use plywood strips stuck with double-sided tap as support? You'd probably want to cover it with wax paper to make sure it doesn't end up stuck.

T

[NevadaBlue]

Thanks guys. I think you are right, tape wouldn’t hold it well enough. I’ll just have to use better supports and fill a few spots. Gotta finish my work space first.
I did spend some time on the design of the galley, but I can’t work on it until I get this entry door opening cut and the door installed.

[swoody126]

NB, the process is quite simple

we use it when butt joining pieces of plywood together to create longer ones for boat building

first of all you use TL's suggestion(since you don't have it on a flat horizontal surface) and screw a piece of plywood behind the joint(wax'd papered of course) to hold the pieces in place while working

then do one side at a time

hollow out the butted edges to accept the FG matte & cloth using an angle grinder

appy FG and allow to cure

once cured take your plywood backer and using the same screw holes and the other side of the plywood wax'd paper covered repeat the process on the other side of your joint

fill the screw holes w/ thickened epoxy

once cured and faired your joint will be something like this

plyjnt6 2.gif (1.57 KiB) Viewed 799 times

it aint rocket surgery

i've done it w/ my Midde School students many times joining 1/4" plywood when building flat bottomed pywood canoes

BON CHANCE

sw

[Philip]

The filler panels are to be glassed in from what I see.

I would cut the filler panels to size. Then use a few drops to of hot glue to position where they need to be. Then start the glass work.

No reason to go to elaborate clamps. The old window opening will provide all the support your panels need. The hot glue will tack it solid.

[NevadaBlue]

Thanks! Now to get ready for the process. Since I am working outside, I’ll have to plan to heat the inside of the trailer and have some heat lamps outside I think. Gotta finish the working shelter first. IF I can get a few warm dry days...

[saywhatthat]

A few thing to think about. A good chance some low life son........ used waxed resin and gel coat. You need to grind all the shine off the back and clean real good dam wax . Then we use thin tin as backing pop Revit to hold in place .with heavy plastic drip cover. To form a seal between the glass and tin. Most wax paper is not like it use to be. will stick. If you can save fiberglass cutting dust .To use for thicking first coat use as gel coat. yes I am cheap. then do your layup. Make sure taper front and back . USE RESIN WITH NO!!!!!!!!!!!! WAX .When resin goes tacky cover with cheap car wax .easy to wipe off.

[NevadaBlue]

Thanks!