customizing a car hood

admin

so i have been asked by a friend to customize his sons hood b/c he has a civic hatch with a j series in it (v6) and it sticks about 4 or 5 inches out of the hood so now he has about a 4' by 2' hole in his hood with a motor sticking out. these number are not correct im just throwing them out there. so what i want to do is use the body lines already in the hood and just come up on the smoothest angle possible to clear the motor and still be able to shut the hood. it does not need to be perfect but i want to try and make it as close as i can i have ms tigs and migs to work with and pretty much unlimited resources to work with. so let me hear how you guys would go about doing this (type of welder thickness of materials type of weld like the tack tack tack method or just tig the whole thing or mig the whole thing) i do not have exact measurements at the moment i will upload them asap. i have 3 hoods to work with a the original with the hole in it but still has the body lines and 2 extras.
Reply:this is what the hood/engine looks like now (this is not his car)
Reply:I would hand form a piece of sheet metal into a nice smooth bubble which roughly follows the contour lines of the exposed portion of the engine.  Weld it to the hood, smooth everything out, then send him off to the nearest body shop to have his hood finished and painted.  Try to go for a manufacturer look as much as possible so it's not just some silly looking add on.--Wintermute"No man's knowledge here can go beyond his experience." - John Lockewww.improvised-engineering.comManufacturer Agnostic:Blood----------Sweat---------Tears----|------------------|----------------|----Lincoln Red, Miller Blue, Esab Yellow
Reply:we (me n a class mate who does alot of body work) were thinking about cutting the hood right in the middle on the raised part where it is no longer curved where it is straight vertical and just adding steal there and bondoing it instead of cutting the whole top off and making a new one. and we are doing ALL the work as in bondo sanding and painting it we have axcess to pretty much anything including a pro booth and all types of welders,saws,bandsaw,portaband,plasma everything its a school so remember we can use any techniqe.
Reply:like this but not cut the whole hood in thirds leave about 3-4 inches not cut and raise then add metal from the inside and weld it in and bondo it
Reply:but i think im going to have to make two bends because if i just make it a straight cowl it will end up being 8 inches or so up and that is not acceptable we want this to look as stock as possible.
Reply:If you have access to all of the tools you need, form a new piece of sheet, (same thickness as the material the hood is made out of.  Shape it with an english wheel, smooth it with a planishing hammer, fit it appropriately so it looks stock to the vehicle, then weld it in.  Make sure you keep everything very smooth.  Remember, bondo is for filling in minor imperfections (very minor) it is not for building up or filling in major imperfections.  Do the work right...if not for the owner of the car, then for yourself.  In fact, most importantly, do it right for yourself.  Learning to do things correctly, with pride in your work and without cutting corners is paramount.--Wintermute"No man's knowledge here can go beyond his experience." - John Lockewww.improvised-engineering.comManufacturer Agnostic:Blood----------Sweat---------Tears----|------------------|----------------|----Lincoln Red, Miller Blue, Esab Yellow
Reply:thanks yea the only problem with making the whole thing from a new piece is i have not made anything like this and i dont want to screew it up i figured with adding a piece we wouldnt have to worrie about forming a whole new piece and with cutting it where it perfectly vertical so we wouldnt have to create curves or follow body lines instead we can just add the strip but i will talk to my friend and we also have to talk to my teacher and see how much time we have to work on it because we only get about a hour and a half to work 4 days a week so i cant take a few weeks of class to do this it needs to take 2 weeks MAX if we can milk it that long.
Reply:because of heat, vibration & added weight you should NOT use much bondo on a hood at all unless you like the look of cracks as graphics... also make sure you leave some extra room for engine movement which can be quite a bit in a fwd transverse design, especially with a motor that's too big to even fit under the hood in the first place 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:yea im trying to use as little bondo as possible but im trying to think how much higher then the engine it will have to be i want to make braces under the hood so it has strength but he actually doesnt want me to cuz the most commonly thing said by my honda friend "power to weight ratio". and he brought up the fact that fiber glass hoods are really flimsy and if he has to he will just put hood pins in. i want to put suports in but its what the customer wants. But you guys are helping but i need to know your opinions aout what type of welder what style and thickness.... what i was thinking was the same thickness as the hood or maybe a tiny bit thicker but he will probly complain cuz the weight so scratch that and tack it all with mig maybe tack the whole thing or tack it with mig the tig the rest but im no pro at tig so im not sure if my tig welds are worth all the cleaning up but tig welds and easy to clean up with a grinder and sander.
Reply:most body shops would just tack and fill with the MIG.  I'd say screw his horsepower to weight ratio, if he can't deal with the 2.5lbs extra to do it correctly, tell him to go buy an old muscle car and build a blown 800hp 440ci for it...or tell him to go have Speedcraft Composite in CA make him a complete custom hood...shouldn't cost much more than buying a brand new car.  I'd use the same thickness material as the hood, shape it, do it right and tack it all in with the mig.  Make sure to stagger your tacks around and take your time so the heat doesn't warp the hood.  Keep everything as smooth as possible so you use very very little bondo.As turbocad said, make sure you leave enough room for engine movement...the movement can be kinda dramatic.--Wintermute"No man's knowledge here can go beyond his experience." - John Lockewww.improvised-engineering.comManufacturer Agnostic:Blood----------Sweat---------Tears----|------------------|----------------|----Lincoln Red, Miller Blue, Esab Yellow
Reply:Forget the hood. Who needs those
Reply:Plexiglas & vacuum forming.  That will solve all the problems.MarkI haven't always been a nurse........Craftsman 12"x36" LatheEnco G-30B MillHobart Handler 175Lincoln WeldandPower 225 AC/DC G-7 CV/CCAdd a Foot Pedal to a Harbor Freight Chicago Electric 165A DC TIG PapaLion's Gate Build
Reply:then thats what im going to do tack wit the mig and yes i will be jumping around to keep heat low. and the whole power to weight ratio im on the same page as u id rather have a back seat and no holes cut in my bumper n just have a bada$$motor but try explaing that to a import guy and all they do is saying your a hater and blah blah blah so i dont even care anymore opinions dont motivate me money does so if he wants to pay me to take a dump on his hood i will . so thanks for the info when i go back to school i will be doing some rocker pannel work on a old vw bus. then its straight to the hood ill take as many crappy phone pictures as i can.
Reply:I bet the guy has got a little dick. Major overkill.I don't know anything about honda motors made in the last 10 years or so.  I do know there are guys out there making 600+ hp with 1.6 and 1.8 liter engines. Traction becomes a major issue.As far as the power to weight ratio.....he's already screwed up the balance of that car.  There is no way to make a bubble that big blend in and look factory.  If you're going to do it, make it bold and look like it has a purpose, but still compliment the body lines.My name's not Jim....
Reply:indeed on the over kill part the kid who has the car didnt build it. his dad built it more as a challenge to have a fairly unique car cuz back when he did it the was maybe 5 - 10 j series swaps. im thinking i might just might be able to make it look kinda stock because you can build one with a diffrent set of mounts and it will fit but has really bad ground clearance which is not an option with the crappy roads in ny. but there are also other ways like a diffrent intake plenum which will drop it a 2 or 3 inches and there is a spacer that you can remove which drops it another inch so after doing that the motor barley sticks out almost to where you can cut the suports of the hood and a hole about 4" by 2" which drastically lowers the hood.so i have to see what year the motor is to make sure he can get the intake and remove the spacer cuz some years dont have it but he has the tl type s 6 spd so i think he does
Reply:Originally Posted by MarkBall2Plexiglas & vacuum forming.  That will solve all the problems.
Reply:if I had to build a steel hood like that without the luxury/budget of doing it right with an english wheel/power hammer type deal  I'd get 2 aftermarket hoods, skin the center of one & build a rise onto the second one with it.frame out the opening in the inner reinforcement layer first & the upper buldge layer would be stiff enough in the center because of the buldge to not need reinforcing in the center. I would probably overlap the sheet metal & spot weld all around then stitch then use a fiber reinforced filler for the first seem fill. another better way IF you can get the fitup real nice is a bonding adhiesive to meld buldge to hood, a lot of advantages to bonding, but only if you can get the fit together right,you could weld all the cuts & patchwork to the buldge itself & make something that fits the bottom open cut hood well enough to bond the main seam all around.    a pair of aftermarket hoods should be under $200 I'm guessing & would be all the materail you'd need to do it 100%. you will def have all you'd need far as material but how well you shape & blend them is all on you, not an easy task at all to do well, I could see 30 hours or more here to do it nice...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:HMMMMMMMMM!  Gift wrapping an elephant, huh?I would go for something of a "cowl induction hood" by replacing the center section with a raised panel and leaving the back open toward the windshield low pressure area.  Since you already have the hoods to butcher for panels, I would suggest just making the opening incision along the high crown lines where the stock hood bumps up and then repeating the process on one of the donor hoods for the panel.  The replacement panel will need to be narrowed and lengthened to fit over the opening, so you will end up using the second donor hood for that section.  After mocking up the top panel over the engine and checking everything for clearance, you will have to fab the "pie slices" to mate the top to the perimeter.The high tensile steel on the car is going to be some tough stuff to work with because it shrinks like crazy when welded and work hardens quickly when hammered to stretch the welds.  For that reason I would probably just make the replacement panel from 19 or 20 gauge DQ steel and then only have the joining welds to deal with the high tensile.Any way you go it is going to be challenging.  The hood probably is going to have a tremendous amount of flex to a panel that large with no crown lines for support, so you will need to add support stucture behind the skin.  Bondo will just compound the flex problem up to the point where it cracks and flies off.  This really isn't a "beginners" project.  I have been pounding tin for 40 years and would consider this a challenge, especially if done to metal finish (no bondo).  The welding is pretty straight forward, though I would tend towards the TIG for the added heat control it offers over a MIG as well as being able to control the filler deposit (shrinkage control).  Work the welds as you go because waiting until you finish welding and then trying to straighten out the resulting pretzel is way more difficult, if not impossible.  One of the first things I would do is some "wire forms" to get some idea of the profiles I want.  Go over to www.allshops.org and search for some of Jim Bailie's old posts on wire bucks to get an idea of how those work.  Here is an example of one of Jim's wire bucks   (Jim Bailie photo, Thanks Jim)The buck is simply in place to give the shape and support during the fabrication and will be removed after the part is completed.   Preliminary forms can be just welding rod or fence wire (anything stiff enough to hold the shape and easy to bend with finger pressure).  Once you have the shape then you can formalize the buck in rod stock or wood (both work well so it is your preference).Like I said before, it is a challenging project.  It is doable, but you are going to learn how to dance with the large lady.  She's gonna kick your butt more than a few times.  When she does, just go set quietly in a dark corner and reflect on what you did wrong, where you got behind the curve, or how you can get ahead of her.  With a bit of practice you will begin to anticipate her and give her what she needs before she turns nasty on you.As others have stated there are tons of places that sell all sorts of "bubbles, scoops and assorted other bulges" made of varying grades of composites, that can be glued on.  They are cheap and easy.  Just remember the old metalshapers addage though"Steel is real,Putty and paint ain't"And if all else fails, "Beat it to fit, and Paint it to match"RogerOld, Tired, and GRUMPYSalesman will call, Batteries not included, Assembly is required, and FREE ADVICE IS WORTH EXACTLY WHAT YOU PAY FOR IT!Dial Arc 250HFThunderbolt 225 AC/DCAssorted A/O torches
Reply:ok lots of help guys thanks see i have a english wheel however autobody stole it from us and i cant take it back b/c there making  body pannels for my teachers porsche so not only will auto body not give it back my teacher is not exactly going to be on my side. and we do not have a power hammer in my class. AND NO   i will absolutly be gluing or riviting or however you want to go about it a fake autozone cowl i will be building this from steel  sweat and blood with maybe a hint of bondo. i think im going to make a steel wire form that is removable b/c i will build it on the car then take it off and bring it to the shop. i cant take the car b/c the hood is a surprise for the kids birthday. now as far as the cowl im not sure if i want to make it get skinnier as it goes up which would involve cutting and shortening the top of the hood of just leaving the vertical straight up and down im going to have to look at the car and see if its more rounded or squared off i belive it rounded i think its a civic ek but dont quote me on that. so idk yet i have so many ways i want to go about this but im not sure of which im going to talk to my friend more and we will come up with a plan and i will post pics as soon as i get done wit the bus
Reply:so i got the hood from my friend. and he took bunch of measurements..... which turned out to be a big issue. He took measurements but he was not clear if it was how high the hood needs to be or how high the motor was. so i was not sure to add a half inch or so for motor movement. so i did not get to weld anything today.... first i started off by taking flap wheel to the body line where i was going to weld on later while it was still one piece. then marked it where it was flat.then i cut where the body line is flat.then i finished off the cutting on the bottom but i did not cut the whole hood into thirds. i left about 2_1/2"  at the front so i could keep the hood as one piece .After that i attempted to lift the center of the hood but with the supports it would not curve (as expected). None of us liked it and by the time it was by the window it was sticking up about 7-8inches in order to clear the motor. i took a pic on my cell but you can barely see it and that was not an option to have it that high. So the suports had to go (as expected)...I cut out the sides and front and seperated the top by unfolding the stamped fold.....
Reply:So now i had this...This allowed for alot of flex which is what i need to make the cowl a curve not a angle. So this is a ball park estimate of how high the hood will be. I was going to weld it today but my friend never brought the car to my house so i couldnt confirm how it would fit up... so this should be very similar to shape obviously with sides welded in. Which will be out out of 22ga sheet metal that john at All American Fabrication and Maintenance cut for me.http://www.allamfabmaint.com/and for all those that find something to point out.... heres my baby thats right strapped and chainedSo that what im at for now until i can put it on the car and confirm everything will fit/clear. i will keep you guys posted with many pics i finally figured out how to upload with the camera.Last edited by himsa169; 03-26-2011 at 11:23 PM.
Reply:probably should have tied the far left and right underside supports together so you could remove the center support and still have them locked in the same position. OR maybe just laying the hood on a welding will get the hood back in its proper alignment. Id suggest tacing the hood to your table in many spots so you can weld the cowl back together and try to prevent some of the warpage. Looking forward to seeing the finshed hood. i bet it will look great.
Reply:yea i probly should have tryd to keep the left and right together but i didnt take enough time to think it through well at least I measured a bunch of diffrent ways before i cut. but  i am going to bolt the hood to the car make sure it clears the motor and make sure the gaps on the fenders and grill are right then im going to tack it on the car. Also i measured in the center, front, back, and side to side so i know where the left and right wings should be at.
Reply:maybe setting the hood on the car with the center cut the way it is would allow you to see just how much clearance is needed?yea thats what i plan to do when i actually get a hold of the guy so i can lay the hood on put shims in the back so it levels out and looks good then make a cardboard cut out then trace it on to the steel cut and weld sounds simple but i dont see it going that easy without something happening.
Reply:so my friend cam over yesterday and says it needs to be done asap b/c his buddy has a booth to use fri. and sat. so i lay the hood on his car cut a piece and weld it in like so......then it got really late. so we waited til today do finish up at his house or so we thought...so we got both sides done and we were not really feeling the lines. so we decided to add another piece at an angle. so i cut it out and at looked so much better b/c the car is very round and the old setup had straight and 90degre angles where the extra piece was at more of a 50-60 degrees which looked alot better with the more rounded cowl. so  this is what it looks like (hard to tell the diffrence in the pic but it looks alot better)  also btw the cowl is 4 inches which is not hard to see over i also capped off the inside channels the suported the hood before i cut it out and added a extra piece of metal on the corner (which did make quite a diffrence the hood flexes alot less with it on both sides.so at this point i finished the passenger side and will be going over tomarro to finish rounding off the driver side.
Reply:and also in the pic thats my mask with a led light epoxyd in and it isnt used all that often but when it is its a life saver.
Reply:Keep us posted... Im curious to see how it turns out...GL!
Reply:so the side in the pic i welded a little faster then i wanted so it warped as you can see.. but the other side looks great with min warpage. however we decided that we are going to fiber glass the seams and the bondo/ice it.