trunk hinges for a fiberglass trunk lid

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hey guys, I have a project in my shop and I could use a little advice with it.long story short is the car is an old box nova, back halved and tubbed and it has a fiberglass trunk lid held on with the typical dezus fasteners all around the edge of the lid. car also has a fuel cell in the trunk. now this is an 8 second car but it is also driven on the street quite a bit and the problem is that with a small fuel cell this means having to put gas in this thing very often while cruizing around... the owner of the car ran over the trunk lid one day while at home and has now decided that he really doesn't want to deal with these dezus fasteners anymore. we repainted this car a few years ago and went back to steel fenders and are really trying for the stock body look to a certain extent and the fasteners on the trunk realy kill this too, so the plan now is to create a hinge setup for the fiberglass lid.I came up with a few ideas and I decided to build an aluminum inner skin for the trunk lid and bond it to the fiberglass outer skin so I would have a solid base to attach hinges to. the rear deck is very tiny on this thing and the tubs are huge so there really isn't much room for hinges, I decided to build my own. now here is the real question....would 2" square 1/8" 6061 t6 be strong enough to stand up to the vibrations and stress it might see as trunk hinge arms? I will have a conventional latch at the rear locking the trunk lid down but the only thing really holding the lid to the car even when the trunk is closed is just the lock and the 2 hinges. would I be much better off building the actual hinge arms from steel? I know the aluminum arms are going to be strong enough to hold the lid for the most part but I'm not so sure how well this will hold up long term, any input would def be appreciated. I'll get some pictures tonight to show what I've done so far. the reason I really want them to be aluminum is for esthetics and uniform look back there and for trying to save as much weight as possible.miller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:im kind of dealiing with the same thing rite now on copying a $4000 dollar trunk & lid assembly , i pretty much had to fab up from scratch minus the hinges.  Ive becomeing an expert on hinges last few weeks.  I thought i got the greatest conecealed hinges in the world and after i machined , drilled and tapped my plates to mold into the fiberglass for the hinges...I came to one major conclusion....Deck and trunk lids have to have ALOTTTTTT of up^ and inswing or the lids going to hit , rub , or just be and look fukn retarded.  I needed small light ones too..and found the best picture searches to be on ebay useing search words 'hood hinges' and  'trunk hinges' kia , honda , fiat , mg midget and sh;t like that...your going to find that "trunk hinges' have huge throw arms and are going to hit your tubs.  I bet in the end ,  your going to have to go with hood type hinges with the 4 links/joints that push up and out but close flat.  I remember seeing some nice expensive billet aluminum ones on ther i think but mayb to big for that tiny nova trunk lid....i think we may have found some tiny ones with bonus adjustable spring tensioners. Picture looks great and price seems to to good to be true , so we'll see        thermal arc 252i  -  millermatic 350P -   miller XMT, cp300ts, 30a 22a feeders, buttload of other millers, handfull of lincolns, couple of esabs  -   Hypertherm 1250 G3
Reply:when it comes to designing hinges it's all about the pivot point. for something complicated you can do it on paper from drawn parts or even from actual photos. this way you can try many different pivot points and then see how the part flows throug it's stroke with paper cut outs. I've done a tilt nose on a car and designed the hinge pivot point from cutting up a straight on side shot photo, use a pin to locate the pivot point and then check the stroke.anyway this one I kept the hinge design real simple, heres a few pictures in the next post of what I have so farmiller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:miller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:few more pics of my progress on this. I think it's going to be  strong enough...after welding the V part that fits into the rear deck area it turned out  that I needed to bend/spread it open a bit...I tried several things to bend it without sucess. I then got more and more agressive with it to the point that in order for me tobend it open I winded up having to jack up and drop a full sized dodge 2500 ram pickup truck on it and it was still very hard to bend it open a bit...I use all kinds of specialty measuring devices in collision repair and I really wanted to make everything as square and straight aspossible but everything on this car is less than 100% squared, less than 100% centered, so I have to just work with what I have to work withmiller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:I made sure my arms are square and the pivots are square so there is no binding through it's strokeI also want everything to be fully adjustable so I can get pefect fit and perfect gaps all around so I made an adjustable bracket to the trunkmiller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:miller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:miller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:i like your pictures ...i stared at them for a long while. Ive had a wicked old  chevy sitting in  my shop for years. The fiberglass fenders are bolted on the same way the stock ones were , shimmed and everything....well , theyve sagged or something and the gaps hav changed . Ive been thinking for awhile and Your pictures reminded me ,  i  need some kind of structural support for them . How Have you delt with that before also        thermal arc 252i  -  millermatic 350P -   miller XMT, cp300ts, 30a 22a feeders, buttload of other millers, handfull of lincolns, couple of esabs  -   Hypertherm 1250 G3
Reply:a 1/4" round rod to add an extra mounting point in the middle of the fender at the front door edge can help a lot. you can also make a  central support for a big saggy fender with 1/4" round rod and have it flat contact for at least a few inches then cover the contact area of the rod with a rubber hose, kind of like an insulated support  where needed but spread the pressure point out a bitproblem with a lot of older body on frame and sub frame type old school cars is that the fenders do actually add a lot of rigidity to the overall body structure, unlike modern unibody cars that the fenders are really more just cosmetic skin... a fiberglass fender car should be either a unibody car or a frame/subframe car with added reinforcement/ forward bars from the firewall to the frame like a cage car, just putting fiberglass fenders alone on many old school cars can make them very flexy and keeping panel alignment can be a problem. what kind of car are you talking about?miller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:I wish i could hang around a place like yours to see what I could learn. Great work!Dave ReberWadsworth Ohio
Reply:Nice work turbocad6, if you are like me the next issue you will have to deal with is explaining to the customer how you have 30 hrs tied up in his hinge system. Usually all my customers have seen a lot of TV and figure you just "whip" something like that up in a couple hours. My 2 cents on the project is 1) arms are plenty strong enough 2) hinge points may need to be closer to the outside of the car to swing the trunk away from the body. Typically I figure as close to the body as possible on an inside hinge. Work looks good, you should be proud and customer should be happy if he knows what kind of effort it takes to do that. "Anybody can talk $h!t behind a monitor, I let the quality of my work speak for itself"Lincoln Square Wave 255 and 355 Tig Lincoln 255 Power-Mig w/ spool gun Koike 5 x 10 CNC plasma Hyd-Mech DM-10 bandsaw Ineco QB-76 NC tube bender
Reply:Very nice. What is the weight of the fiberglass lid and frame work compared to the stock trunk lid and hinges?
Reply:wow, it's been almost 2 months since I last posted in this thread. man I really just don't have time for projects like this and it takes me forever to get it done. coupebuilder, I couldn't move these hinges out much further than they are because the tubs are in the way. the tubs are massive, and to make matters worse when they backhalved this car they removed the whole rear deck right up to the window on the inside and sheetmetaled off straight down from the back glass so I don't have much depth to work with on the trunk side either. I needed the arms to fold into the recess between the tubs.the weight I'm not too sure of but I believe it's lighter than the stock setup. the hoods and trunks on these cars are pretty heavy, this one feels lighter than I would imagine the steel one to be but I don't have any weights to compare.  figuring out the pivot points was tricky and after it was built and test fitted I did have to make a few adjustments to the pivot point  but I got it working real nice. it clears all around and it's ridgid but also has a bit of flex to it. it can go fully up without any danger of contacting anywhere, even when flexed around when open there's no chance of touching anywhere, all my clearances are nice it's very strong.after it was bonded the first time I had to try and take a bit of a bow out of the back edge of the lid and I was able to place it with 2 milk crates just supporting either side edge with the whole center of the trunk unsupported inbetween, then stand on the trunk in the center with all 200 pounds of me in between the outer supports  and bounce up and down on it quite a bit to try to remove a little bit too much bow in the center... and. it wouldn't even bend much at all.... it didn't crack, it just stayed rigid and pretty much unaffected the 2 skins bonded together make a pretty rigid structureone problem I had is the fiberglass is pretty flexible so it can be flexed into place to fit the opening when installed as intended, when it's pinned down with a bunch of dezus connectors it's forced to line up well as long as all the fasteners are lined up, but now you try to just float this thing in the opening and expect every edge to line up perfect? and at the same time?? that's a whole different story  after I bonded the inner skin to the outer skin and hung the lid on the hinges and closed the trunk the problem became apparent. the seams were somewhat miss aligned, the overall shape and cuved structure was just off a bit and it didn't fit right. the trunk was bowed too much in some areas and not enough in others, it didn't really line up too well and even jumping on it wouldn't change the shape.I had to separate the bond in some areas and reset it to align my seams well, it was a pita and eventually the only way I could get it perfect was to jig it up right in the opening on the body at the time it was bonded in some areas just to take the exact shape.this bonding stuff I'm using is pretty amazing stuff and works real well. without it this aluminum inner skin wouldn't be practical I think. I used 3 tubes initially and then just ordered 3 more to add some reinforcement here and there now that it's all locked into correct alignment, just happened to look at the bill on the second 3 and it's like $180 cost for the 3 tubes of this stuff..... wow, $60 each friggin tube... I knew it was expensive but wow, didn't realize it was that expensive I'll attach some pictures in the next post cause there a bit too large and will cut my text off if I do them in this post miller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:I'll have to put the rest of the pics up tomorrow, photobuckets down for maintenance, for now I got only thesemiller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:the front corners of the trunk were a little more pointed originally but I modified it to a slightly more rounded profile for the extra clearance I needed to go to full wide open with a nice amount of clearance . I also had to shorten the whole trunk lid by about 10mm to get the rear to line up perfect with the rear of the body. a lot of fitting and finessing to get all the gaps perfect on this setup. there's a reason why you don't see too many tubbed out race cars with hinged fiberglass trunk lids I guess  Last edited by turbocad6; 06-22-2012 at 02:27 AM.miller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:heres a few more picsmiller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:andmiller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:well I finally finished this car and it has left the shop... hurray!!! anyway, the owner decided that even though we can now open the truck easily he now wanted to complete the filler neck too, well the original filler opening was smack in the middle of the wheel tub so I had to refabricate the recessed filler opening and move it back a few inchessome pics instead of words donor sheet metal, this chevy has at least a little bit of jap car in it now hammer and dolly, which in this case is a 4 post lift leg extension, just happened to be the right size more to follow....miller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:miller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:and after paint:miller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:and back to the fabrication on the trunk, I had to of course build a latch system, and a spring system so the trunk pops and then stays open...first the latch hold down...this started with new metal as I needed a heavier gauge than typical donor  body panels would give, this is 11 gauge I believe...rough cut with the plazma from a cardboard template I made...miller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:I also made the upper latch but no pictures, you can kind of see it here on the lid...miller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:and then there are the springs... this whole setup is very compact because it has to fit between the tubs and the rear deck is very short, we wanted nothing to protrude into he cabin and there really wasn't enough room for pistons at all so I had to come up with a more compact way of doing itthis is what I came up withmiller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:I finished it up last minute and it left without me getting any completed shots but heres a few of it gassing up and leaving!!!note: filler neck will be completed with the new aluminum tank install... project for another day miller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....Now don't take this the wrong way..I like the design.BUTYou really should have gone over your welds..Post 4..Pic 3..Hole in the corner..Pic 5 major keyhole at the end of the square tube..Pic 8..Weld not complete..I could go on..Judging by the size of the sneakers on the Fairlane (Nice Car!) you may encounter some cracking and breaking in these areas from all the abuse and I would hate to see all that work go to waste..Just my thoughts....zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:I did go over some of the welds, anything that looked really sketchy, but I was afraid to go over anything too much, figured reheating and rewelding was not so good for strength... everything is built pretty damn overkill and way stronger than necissary so hopefully it will hold up well... time wil tell I guess and this car is a 66 box nova...miller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:No kiddin! A Nova!From the back with the cover on and no lights in it it looks just like a 66-67 Fairlane!I want another one.....zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:The trunk stuff is great... but WTF were you thinking when you did the gas filler??? I guess filler can make anything look good.
Reply:ha!, I was thinking " I need to get this done tonight and finish the bodywork tommorow, the customer does not want to pay for a quarter panel to cut a filler opening from,  the customer doesn't want to spend what it will take to do this right, how can I beat a piece of sheet of metal to fit this damn thing?"why, does it really look so bad to you? what about it looks  so bad? I think it's done better than many would do it and it's solid and secure and shouldn't give any problems even with years of use hopfully. lets not forget, this is not some restored show car, it's more a racecar, the lower wheel openings were stretched a lot to fit the steam rollers under there and the quarters already have bondo for that patch job, no real reason to try to go ape**** and get perfect sheetmetal above the molding when right below the molding is chopped up and bondo'd anyway... this repair was done in limne with what the car warrented and what the customer wanted. trust me, if this was my car I would have done it different, but here we have a customer who doesn't want to really spend big $$$hell I almost had to fight with him to just get paid for MOST of what I did do miller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....