Im going to need to build some new interior panels for the rear passenger/cargo area. I can only use pieces of the original interior and I am planning to use fiberglass to build the new parts. Im trying to figure out what base to use for the glass. I built a bit out of foam and it seem to be working ok for me, but i just started glassing and found that fiberglass resin eats foam . So i dont think this is going to work. Now i have used cardboard before, when i built a a/c delete box, and it worked very well. I may try this venue next. Any other ideas? anyone here every try to build interior panels? what did you do? thanks Phil

86TA, try 1/8" thick luan....that stuff forms sorta well. Way back in the day I used to use this stuff called wacky wood. It was basically 1/16" luan, foam center, capped by 1/16" luan...kinda like a "wacky sandwich". Other than that cardboard is probably the next best thing.

I have built many fiberglass panels for demo cars. And there is a 2 part foam that expands like crazy. Tape the wheel well them foam it. Cut or sand it down.Then taped over it (blue painters tape) then one thin layer of resin and let dry then fiberglass mat.

There are many other ways to build it but with foam this is how we do it. The foam we used was from a friend at GM and didn't have a name on the cans. But I am sure you can find it. Don't use "great stuff".

If it was me and I wanted a "factory look". I would cut the panel only where it needs to clear. Then use abs black plastic heat it and form it to the floor board. Then use 3M bumper repair glue & duraglass.

Post a pic of the panel and how much needs to be changed. Also is it a panel that had carpet or not?

there are not carpeted, i dont know what im doing to finish them yet.
basically all the panels are not right, the large ones that sit on the wheel wells would need to be widened almost 2", and doing that messes up the fit to the rear cargo pieces and as well as the sail panel area and the part that would cover the seatbelt and connects to the sill plate and the door jam, which is currently cut in half.

i'll se what pics i can get

a little update

ive been playing around with different ideas and designs, and good old cardboard seems to be the way to go, since i would still like to be able to remove the panels when im done, and blend into pieces of the originals, it seemed like the way to go. I spent a few hours the other day on the passengerside and formed the panel, i may try to figure out a way to add a radius to the inside of the panel, to eliminate the right angle and smooth things, but im still undecided.

good old leftover pizza boxes...



ive got a little more "tweaking" to do on some of the edges an my transition on the back, but this side is pretty much together. I followed the radius of the origional bulge on the remaining sides of the panel. my camera batts died so i only took 2 pics, but you get the idea. the board sitting on the carpet is just a catch, I would glass down and onto it a bit, then cut it back to leave a small lip at the bottom, like the stock pieces have.

Do you have any pics of the stock panel without the tape and cardboard? That looks good from every view but the rear. Something with the curve to box. Just doesn't look right. You need a 4th gen curve.

I know this sounds like alot of work but with a large piece like that we would make MDF wooden forms. Covered with Fiberglass or flex board then make a one piece fiberglass cast. The cast would then be 3M bumper adhesived on. Once it is all smooth it would be texture match it and then buy the matching GM code dye and call it done.

na, i dont have any pics of the panel before i started cutting....

as for the round to square transition, i dont really know what else i could do there without remaking the entire rear interior.

what does the rear interior of the 4th gen look like, ive never really looked at one?

I forgot the year(1997) that didn't have the rear speakers but these panels.
Look at the area right where the belt comes out. It looks like a square but has a softer rolled edge.

well what i will probably do is, glass what i have, when its hard, it will be a bit easier to work with and i can shave the sharp corner off and blend it a bit to create a softer transition. thanks for the pic

you could always cover them in vinyl, and cover everything else too, it would match perfectly.

i was thinking about doing this, just need to find a place to buy said vinyl.

I bought vinyl from Joann fabric, looks like theres a bunch in NJ. They sell it by the yard on a 5-6ft wide roll

thats good to know, i will look them up
thanks

Is the blue painter’s tape enough to release it? I’ve used duct tape with a heavy coat of wax on it before but even that sticks at the seams.

What’s wrong with great stuff?

How do you texture match? I’ve been trying to figure out how to do that with a few parts forever…

No we use turtle wax and lots of it!

Great Stuff is bad.
1-hard to cut or sand without breaking up
2- can start rust/mold
3-sticky and messy
4-Resin can melt it

For texturing. I have seen it done with a quick dry spray paint. All you need is to keep the can far far away so it drys up a little before it hits. There are also some company that makes a texture paint. We have you it on many projects. But they are small iteams like a-pillers,tweeter pods, and kick panels. The best way is plastic form molds. We did a airbag cover like that. Made a quick and dirty fiberglass cast, then went to a plastic mold guy(local). He casted a plastic mold of that and then he used heat and a texture tool to make it like the leather dash. We still had to dye it as it was gloss black. Came out amazing. But cost was $200.

I have done demo cars for Ford,LUND,Pioneer,Alpine. Most where just local rep cars with new or prototype part and product. Or demo electrics or dash layouts. And have done more glass work than many! But don't anymore! I will try to get pics of my work in my TBSS that is paint matched!

83, that texture you see is an injection molding industry standard. The texture is basically acid etched into the cavity and cores forming the plastics. I'm sure GM's specific texture is one of their own, based of an industry standard. Look up MOLDTEC textures. There a company thats WIDELY used in my industry for textures. Moldtec probably has something similiar to what you want but again, they only do steel.

I looked up moldtec and kept getting sig moldtec with some mentions of plastic textures but all the links were clear plastic bottles.

Let me tell you what I’m doing, and maybe you guys can give me some idea how to make it look right (and although I’m sort of hijacking the thread, I believe that the answer may help the original thread also). It’s a center console for a my ’92 full size chevy (I bought it as a beater/tow vehicle/parts hauler but it’s getting a lot of use as a family trickster, especially with the dog only liking riding in it). Basically it incorporates the stock console box, cup holders, and then the whole area in front of it, around the 4wd shift lever up to the stock dash with a sub enclosure built into it, 1800watt power inverter with AC and DC plugs, sub amp, sort of a catch all area in on the top/front, and I’m not sure if I’m going to move the radio from the stock tape deck location to the top of the console (the stock location you can’t reach from the driver’s seat but the remote is quite good so it’s not really a problem).

It’s mostly built out of MDF with some bits of fiberglass and the consol lid and cup holders/parts out of the factory consol (don’t worry, if you’ve seen some of the other stuff I’ve made you’ll know that I’m quite anal retentive and if it wasn’t for the different colors you’d swear that most of this was machined out of one sold block of something, it would look OK spray bombed all one color but the textures wouldn’t match), but I’m quite willing to give it a full coat of ‘glass/glass resin if that is the way to get a finish that blends into the rest of the interior. If I couldn’t figure out how to make the rest of it work, the plan was to carpet the bulk of it and figure out some nice trim for the pieces that would still be exposed, but I’m not thrilled with that idea. I’ve also considered trying to find some plether/vinyl to wrap it in but I don’t know how durable that would be.

update

i glassed the passenger side piece, and really didn't like where it was going. WAY too much work and matching the other side would be a total pain, also involved cutting the piece that goes over the belts and connects to the sill plate and rebuilding that whole piece. It was just snowballing into a real mess.

I abandoned that side, picked up a new piece off ebay and started on the driver side in the meantime. From the work that i had begun i found issues with fiberglass and the interior panels. Glass resin does not really like to stick to the panels, even when cleaned, sanded, etc i could not achieve a very good hold, i could get it to a point where it was acceptable, but not working very well. A lot of that was also affected by the fact that i built a large amount of the panel from glass and joined it to the existing panel at a weird angle. I experimented with a few different ways and adhesion cements, glue, heat, trying to find the best way to stick pieces together. After all that i ended up with fiberglass, nothing really seems to stick to this stuff. I found that you need to sand the joints very well, getting them nice and rough and drilling lines of 1/8" or so holes in the panels at the connection. When glassing, i taped over the backside and the resin filled the holes and made a little "spot weld" type joint that greatly increased the strength.

So the cutting of the driver side started, i opted to cut the panel 1" in from the side so leave me a little lip to glass to. This time I'm just extending the panel and gently angling it back to the rear plastics for a nice smooth transition that almost looks factory. I'm moving the seat belt panels inward as well, to mate-up with the widened panels. I cant use the backseat anyway so no loss here. I picked up a set of those parts from ebay without the belt holes, one less thing for me to fill, and I'm going to have to cut them in half, and extend them as well, about 3" and they should joint everything together like factory and tire right back into the sill plates. I have the side panel glassed, just started on the inside of it tonight.

When it dries I'll grab some pics, and see how it fits.

86TA, fiberglass resin won't stick to abs or polyproplene (I believe those are the materials for interior panels). What you could do is think of a wooden boat and how it has sections as you move down the hull. Look at your panels from a front view and side view and use MDF to cut "sections" like a hull. After that you could simply cover them in fleece then do your fiberglass, building up the areas you needed to with Bondo or something.

i though about that, but that would entail building the entire interior, and I dont want to do that, im trying to keep it looking somewhat factory.

As it sits, the connection is pretty damn good, i just dont know what will become of it once its sanded. Im still planning to cover all the interior pieces with vinyl, or fabric of some kind for a cleaner, less cheep plastic look.

and i think its polypropylene, not ABS, being that ABS cement wont stick to it either

ahh...you did the model glue test? Then its a polyolefin. Most like PP like your thinking. Why couldn't you take a factory look approach with wooden sections covered by F-glass?

i could do a factory look with wooden section, but i would still have to tie back into parts of the factory panels, or build everything from scratch. Im still trying to avoid that.

I checked out the piece just now and it seems pretty sturdy, if i get time this weekend i'll start sanding things down and filling a bit and see if it falls apart or not.

Only other way I can think of fastening to stock panels is screw from behind the plastic into the new structure.

NO NO NO

It is best to make what you want out of fiberglass. Duraglass if major shapes and strength is a issue. Don't worry about the glass not sticking just that it looks good when it is done. Then there is a 2 part glue that has a special "gun" and replacment tips. it is called DURA*** I have 6 tubes at the shop but can't remeber the name. ?Durabond?This is the strongest body glue available. We have used it on metal,fiberglass,plastic,wood with no problems.

But try not to over do it cuz even a 80grid air sander has a hard time with it.
One marble size drop on a plastic bump and we hit it with a hammer and couldn't break it off!

Stay away from Bondo. Unless it is super super small finnish coats to hide sand marks. And only on fiberglass not the plastic.

I have 2 dashes moded for DVD screens that some kids did. Looked great and had a pro paint job, but then the heat and the movement cracked the soft bondo. So $125 do the crapper and he pays me to redo a new dash with my plastic glue.

update and pics!

this is what im working on now, the passenger-side experiment is in the trash and this seems to be working pretty well and keeps a bit of the factory look as well
It still needs some more filler, sanding, ect...

The carpet has no pading under it so its a little low, im going to fix that.


from behind

there is a little high spot im going to have to shave down.

In this one i have the lower b pillar? piece installed on the new piece showing how much the front has moved, its about 3-3.5" more inboard. The plan is to cut the b pillar panel at the tape, put the door trim side on the door and fill in the gap, sounds like a plan, well see if it pan out. So far im liking it.





I cut the panel almost the whole length front to back leaving a 1" lip on the sides so i have a flat surface to glass to. Before i started glassing, i scuffed up the surface really good and drilled a shatload of 1/8" holes down the seam so the glass will have a plug to fill and help the strength. Once the top was finished i glassed the inside too really good to add strength. It seemed to work well, i had the panel hanging from a tree while i was working on it yesterday and the wind took it for a spin. It didnt crack or anything so im happy

When im dont im hoping i can paint the panels, and not cover them.

Have you considered Using a plastic welder and weld the pieces together. You can get a cheap plastic welder from harbor freight. You can also get the filler rod from them. Once the pieces are welded together you will need to go to a autobody store and get some plastic filler. It mixes just like bondo but is flexible, won't crack, and is designed to adhere to plastic, and polyproplene panels. I had cracks in my rear bumper and welded the cracks together and then filled them with the plastic filler.

its been a while so here is an update

Driverside is moving right along, most of the shaping is finished, just need to finish a couple edges and smooth the whole piece, passengerside is started and coming along as well, the rearmost piece is almost finished, just a small spot of shaping and a bit of smoothing, the next piece is still in just rough glass, and the door jamb piece is in need of a little more filling/shaping and its almost ready.

I havent had the car for the last month, getting some body work done, so i couldnt finish up too much without test fitting again, i through the pieces in today to see where its all at and its all looking pretty good.



driverside almost done with some test paint


passengerside still kinda rough


driver


passenger



the panels start to spread about 24" from the rear of the car and end up about 4" wider by the door jamb, covering the metal work quite nicely and still keeping lines similar to stock.
i have some time off coming up so maybe i will get some time to finish some of it, it would be nice to have an interior again

That's all pretty impressive man. I'm still in awe at the fat meats you have that car rolling on. You ever come to a conclusion on your LCA's and if that was the design you thought was the "one"?

very cool. Have you done a test fit with the back seats installed yet with the panels widened? or will you not be running with them?

back seat? HA! no way is it going to fit, not even between the sheet metal.

Im still on the fence with the LCA's, they are still holding strong but im still not 100% on them.

youd be suprised what a shop can do with a seat.
take it to them with the measurements and see if they cant cut the middle out of it and weld it up. better yet, do it yourself and then send it in to be covered.
instead of having the split pattern in the middle, you could do a pattern on them like normal, just the middle would be missing.
wouldnt be nothing to take up some seat bolt tabs back on the chassis.
be sweet!

^, its not just the back of the seats, each of the bottoms would also be 4" narrower, they would only be able to receive a very small butt, there is really no way to get them in and honestly they were useless to begin with so no loss, i'll make a nice fiberglass piece to cover the void where they used to be and be done with it.

i didnt even think about the bottoms.
doh!

dang, thats starting to look really good.

Question though. Did that panel come without the seat belt "box" or did you remove it yourself?

not sure what you mean, are you talking about the box for the shoulder belt? my car is a 86 it did not come with shoulder belts in the back so the panel dont have that box. the lower section where the belt comes out are from a car with shoulder belts so they dont have the cutouts, one less thing for me to fill.

I mean the shoulder section up top with the box, yes. I'm gonna have to take a look for a set of those, since I dont have back seats either.

Hmm thats pretty impressive stuff. I had to go back and read to realize those panels werent stock! Nice job, very seemless.

As for the seats, i had an idea for the bottom, but not the back side. However someone already solved your backside prob, so heres what you do for the bottoms.

Move the "bolt in " locations over 4" or whatever to the middle. Since the rear seats sit on either side of the tunnel, there is room to play. In addition to the 4" over you could also raise them, with washers or something. It would just require you to take out and weld in the "tabs" for the bolts, very easy.

The seats would be a lil closer together, but it would work. I think its worth it to go the extra mile to squeeze em in, cuz u worked hard on the rest to make it look the way it does, just feels like something is missing without the rears.

my 0.02.

Also, whenever ive sat in the back of these cars (usually while working on them) i tend to use the interior panel as an arm rest. Now that youve "widened" it quite a bit, its almost tempting to suggest that looks to be the perfect spot for rear passenger cup holder . But lets not get carried away....

Nice work.

it would be the perfect spot, but no cups are allowed in teh car.

I really do think the rear seat idea is going to go anywhere, even if i raise the seats to fit them in, they would still be useless, nowhere to install the seatbelts, and the loss of rear headroom would be unbearable.

Thanks for the comments though! once they are smoothed and painted they should be mistakable for stock

here's the thread, wow its been a while and no updates!!

I will grab some pics soon, when i have some more time.

The driverside is ~95% finished. Its all shaped, and painted with a slightly textured paint so it doesn't clash with the rest of the panels. It actually matches pretty well, for the uninformed, the panels will pass as stock. I have only 1 panel on the passenger side to finish when it gets warmer and im done!

This winter was a good test for the panels and the glass joints, i was wondering if the plastic would contract enough in the cold to cause a crack, and so far i have seen temps well below zero and nothing has happened to the panels!
pics will come shortly, sorry for the delay.

i found some batteries for my camera, so here you are!

the space tire cover, its been widened just over 1"


passengerside kick panel, its widened 4", the pic makes the wider area look little darker, but its not. Probably just a slight change in texture that catches the light differently.


driverside panel, side view


driverside panels


more driverside, these are widened 4" and i even was able to keep that little lip, or body line, in the panel through the widened part, next page ( damn pic limit!!!!!)

cont...





so there are still a few spots that need some more fine tuning, but so far im quite happy with how they came out. I didnt grab any pics of the last piece, but i will later this spring when i get back to work on this project, and i will take some more pics of the building/finishing process on that part.

Now i have a large flat spot on the kick panel parts, wonder what i can put there? maybe a cup holder? speaker? other?

what do you think?

-Phil

WOW! Those came out sooo much better than I ever would've imagined! I am truely impressed. Congrats on a job very well done

What paint/technique did you use to re-create the textured finish, it looks like you matched the factory finish very well

the color is almost perfect, but i scuffed and painted the entire panel so there would be no difference.

Up close, the texture is not the same as stock on the widened parts. I kept the factory texture on the sides like where the sail panel goes, just a scuff and shoot, but the rest is a little different. I sanded the rest smooth, then went over it quick with a really course disc, 40 grit IIRF, then hand sanded off the roughness with 220. This left a bit of a texture, then i used a textured spray paint, rustoleum i think, i dont remember the color off hand, but its like a light sand texture? I will tell you what though, it stuck really well to the plastic. I was a little leary at first, but with a good base and allowed to properly dry before handling, it left a very tough surface, it doesnt scratch off, chip or anything.

thanks for the props! i spent a lot of time on these panels last summer and they came out better than i could have imagined too! I have so many hours into these things its unbelievable, but they pass as stock, which was my goal, and i've had to point them out to a few people or else they would not have noticed.

Like i said before, they passed the cold test without cracking, now to leave it in the sun on a hot day and see what happens!

-Phil

baddest thrid gen mod ever!
great work!

what brand carpet do you have in your car? it looks really nice from the pics.
are you happy with it?

sweet pics....now make me a set

the carpet came from classic industries, forget the brand. I have no issues with it, it required trimming and such but no biggie, there seems to be a little too much material on the driveshaft hump in the rear, but thats not the end of the world, i can probably pull it down a little more and get it a bit tighter

sure...... i'll get right on it

honestly, it took longer to build the interior that it did to mini-tub the car, and im still not done.....

thanks guys! once it warms up a bit more, i'll see if it cant finish the last piece.
-Phil

thats my issue.
carpet fits great everywhere but there. with rear seats in the car, the hump looks good, but now im putting a bar in, i was thinking about getting rid of the rear seats.
kinda hard to do when the carpet doesnt fit nice.
thought about buying new carpet(different brand) but its going to be 200 bucks.
for that i can just get the rear seat covered to match my kirkey drag seats and not have to worry with replacing the carpet...
decisions.

hey are thoes 4th gen transam/firebird seats?? bcuz they look exzality like mine!, i got mine from a 94 firebird. i only paid 50 ea. but i got a camaro and they bolted right up like they were meant tp be there lol