I have a fibreglass 34 coupe that I plan to install a cowl vent into, I have an original cowl vent and a new steel cowl vent repair panel. I want to add panel to glass body by either glassing steel panel into body or re producing steel panel in fibreglass and glassing to body. If I end up making panel in glass I will produce some extras to sell to others wanting to do the same thing. I need advice from anyone who has done this before and /or advice on producing a fibreglass item from a steel sample. Thanks in advance. Glen
My 2 cents : there are some newer structural adhesives for the automotive use . Lots of OT stuff is held together with this stuff today . It good stuff and works well . I would trim to get the best fit possible “ glue “ the panel in place , finish over the joint and be done . Just my take on it .
@deathrowdave is correct, modern stuff is glued a lot! However, it isn't edge to edge (butted) but lapped. You would want a lower flange to be the attachment point. It should have a deep enough step to be able to work with a 'glass body thickness.
@RodStRace is correct about @deathrowdave being correct about gluing that panel. You need to sand the glass to create a mounting area, so the steel panel sits slightly lower that the cowl. I texture the back of the panel (glue side) to give the cement something to grip, the glass is porous after you remove the gelcoat so you may want to apply something to guarantee adhesion. Hoods are tough to join metal and glass because they are flexing and subject to massive heat changes. That panel should be just fine glued on the cowl though.
Actually, I was thinking of his remark about duplicating in glass. I'd have a lower flange, grind/sand to fit under and glue in. Then just have a small gap to fill with kitty hair or do the full 'glass patch on top. Helped a friend bodywork the side glass cover panels on his OT Aspen to the steel shell. We tried to use the best stuff, but it still hairline cracked after paint.
I think I would reproduce the opening and recess with layers of plywood glassed in and smoothed. this would make it strong enough to screw a hinge to and room to add a drain.
@Bandit Billy is correct about @RodStRace being correct about @deathrowdave about glueing that panel. Go for it
Try getting in touch with Barry (ratrod0) he built this glass 1932 5 window coupe and added a cowl vent, tilt windshield and a roll down rear window. HRP
Thanks for advice guys, seems that glueing steel panel to glass body could be the way to go. What glue would be recommended / what have others used. How would this differ from reproducing steel panel in fibreglass and glassing in place. Wouldn't a fibreglass panel eliminate any issues with dissimilar materials, or am I making to much work for myself. Glen
fiberglass does not stick too well to steel . at least what I have experienced. I have coated the steel with plastic filler, which does stick to steel well, then put the fiberglass to the plastic filler, which does stick to it well. I would just use glass and wood.
https://www.3m.com/3M/en_US/bonding-and-assembly-us/structural-adhesives/acrylic-adhesives/ https://www.3m.com/3M/en_US/bonding-and-assembly-us/structural-adhesives/epoxy/ I'd ask their tech line. They have a lot of different stuff. I'd still pull a 'glass part from the steel, not bond the steel to the glass body. Extra steps, but assured less issues.
I recently purchased some Crestabond glue, ( not cheap ) industrial strength stuff - recommended by a guy who bonds glass scoops to steel bonnets. I will probably make a mold of vent in fibreglass anyway ( mainly for the experience and to possibly sell a few to others wanting to add a vent to there glass bodies ). Anyway I started to recess body to accept vent. Thanks again for advice. Glen
I used Lord Fusor bonding agent to bond this steel firewall I built to glass. At the time the 3M stuff required a special gun. I think the Lord fuser used just a caulk gun. Did this about 8 years ago. Has held up well. no cracks to the bond or paint.
At this point in time I plan to glue steel panel in place ( although making one in fibreglass is still an option ), today I fabbed up a support frame that will hold panel in place and have provision to hinge vent. I still need to fab up handle assembly to open / close vent. I have a plan in place and hopefully will fab handle on next day off, a few pics. Glen
I glued vent panel in place today, hopefully the Crestabond glue system does what it says, a few pics. Glen
this project reminds me of a mud puddle: you can't tell how deep it is from the top. never realized how much work would go into what, from outward appearance, looks like a little hole in the car. kudos for such a thorough & neat job.
Thanks S.E. Charles for kind comments, some times this project feels more like quicksand than a mud puddle, but it takes small steps to achieve the end goal, lots and lots and lots of small steps. Today I applied some fibreglass reinforced filler, still need a final skim but its another small step. A couple of pics, Glen
Started fabbing hinge assembly today, only problem was there was no room for lever under dash as brake booster in the way so I decided to poke it out the dash, happy with the result. Still a lot to do - I may make a a nice surround lever either riveted or bead rolled or both. I also have to work how to keep open and closed. Glen
pretty elegant solution to the operation phase. Q: above the cowl lever is a little bump in the dashboard. is this where the turn handle for a tilt-out windshield mechanism would go?
I like the term elegant, I plan to shorten lever and make a fancy bezel / surround that incorporates a way to hold open and lock shut, I have a plan in mind, just need a couple of days of work to fabricate. Yes that little bump is for the windshield winder, I have a complete winder assembly and plan to make the window wind out if possible, I have a couple of old front window surrounds but still need the bottom section in order to fabricate a complete screen. If for some reason I cannot have a wind out screen ( there is not much room in there for the winder assembly ) I will still put winder handle there to simulate a working screen. Glen
I spent about 2 hours in shed today, this is what I came up with. I plan to make a little smaller and shape similar to center of dash and recess in by machining around the inside edges of bezel, a few pics, Glen
A few pics of todays progress, I now have a working vent. I'm not 100% sure if I love it but I do like it, I will wait until I have gauges, steering wheel, glove box etc. and then see how it looks. Glen
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