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I understand totally, have two of my own that need attention.


Unbolt the hood hinges and remove the hood, again upside down on the work surface. Use a pencil and mark the inside edge of the surround onto the hood panel. Remove the screws, separating the parts. Now it's time to reattach the hood panel and surround into one piece. This is best done with two people and both have to work quickly. Simultaneously mix up two fairly large (half pint each) batches of panel adhesive. Apply liberal amounts to all matching seams, one person working down each side. Work quickly as you need to have the pieces matched before it begins to harden. It doesn't matter which half you put the adhesive on, just do it quickly and using the screw holes align the panels and re-install the screws to hold it in place. Clamp the edges using c-clamps, vice grips, welding clamps, or whatever you have to hold the matching surfaces together and then while the adhesive is still soft clean up the edges. After it dries, mix up small batches of adhesive and fill any voids along the outside edges or under the edges of the seams. Push it under the seam edge as far as you can with the putty knife. Clean up edges while adhesive is still soft.

Flip the hood over, remove the screws, grind a small dish over each of the screw holes and patch with fiberglass slurry. Fill the dish and push it down into the hole with the stipple brush. Refill the dish just a little bit high. Let cure 24 hours, sand to contour with surrounding hood panel. Refit the hood onto the car, adjust as necessary to align gaps. This hood now fits really well regardless of origin, some light filler to square up edges and it's ready for primer.
That hood-fit looks pretty damned good! Did that take a lot of tweaking/adjusting to get it there during the installation, or was it fairly painless?
 

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Discussion Starter #42
Not allot after the support surround is contoured, that is the tedious part. The hood skin gets aligned and fitted, drilled and the screws position it. Final fit is a repeat of the fit before removal. I used one 1/8" spacer under the DS hinge and a 1/16" spacer under the passenger side hinge. Those were installed during the first fitting of the support surround.

I hope that answers your question.
 

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Thanks for this write-up. You are doing freat
 

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Discussion Starter #44
New Bumpers (Front)

The bumpers arrived in great shape. They were packed well in sturdy boxes and no damage by the shipper. Yea!!! :thumbsup: This being my first experience with the Tru-Flex bumpers I was anxious to work with them. The finish is semi gloss black jell coat and the first impression is one of a quality product. The front was unpacked first so started with it. The instructions tell you that removal of the rubber urethane supports may be necessary and that with the fiberglass bumpers they are not required. The fact is the bumpers won't fit over them, at least not on the '78 I'm working on. The heavy rubber support behind the license plate was removed, this left the plastic egg crate support. The bumper wouldn't fit over that either, it was hitting the bottom most extensions and at the top inner corner of the grille opening. I trimmed of the bottom 1.5" or so and tapered the edges at the grille opening corners. It then fit over the crate support and I was able to test fit the bumper.

It actually fit pretty well, I clamped it into place, marked the holes, removed the bumper and drilled the mounting holes with a 1/4" drill bit. The marks matched pretty close to the indents cast into the bumper. The original metal strips of studs were reused and I installed them into the drilled holes. Some fitting (elongating holes) was needed here to get the outside edge strips into place. I held off on installing the metal valence support on the bottom until the bumper could be fitted. Installed the bumper and got the studs through the holes in the body on the first try. That never happens, I've concluded this is because the new bumper is fiberglass and doesn't flex as the urethane does. Loosely install the nuts on all the studs.

Starting with the two center nuts, match the bumper contour to the car and tighten the nuts. Working outward and alternating side to side match contours and tighten nuts to secure the bumper. In a couple places I used a pry bar to hold the bumper up a little, on the sides clamps helped to hold them flush with the body while I tightened the nuts. With the bumper secured I centered the lower valence support and marked holes for the pop rivets and bolts. The bolt holes matched the slot indents in the bumper cover exactly. Bolt holes were drilled with 5/16" bit, rivet holes a 3/16" bit. With the holes drilled an attempt to install was rejected by two bolts sticking down from the center bumper support. I cut the protruding threads off at the nut and then it fit under the bumper cover where it was riveted into place. Test fit the valence to verify bolt hole locations.

Hoo hew, :cheers: bumper is on, bolted up and fitted. Using a block and 100 grit paper I sanded down the matching edges that protruded beyond the body. The worst were on the sides, sticking out beyond the body about 1/8". I sanded half off the bumper and decided to fill the remaining 1/16" on the body to match up the contours. There are a few low spots along the top edges of the bumper that need to be filled but overall a good fit. Because these are fiberglass it's acceptable to add filler as you would finish any other panel. When done I can visualize these bumper contours matching the body perfectly.

The video shows the bumper bolted up with edges blocked down. No filler added at this point.

https://youtu.be/mm_bfX_sj9k
 

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Discussion Starter #45
New Bumpers (Rear)

The rear bumper was about the same as the front. The instructions again tell you that removal of the rubber urethane supports may be necessary and that with the fiberglass bumpers they are not required. They also tell you that the tail light support brackets must be removed or cracking is likely to occur. The rear has rubberized supports, one on each side of the license plate and one in each corner. The license plate supports were removed completely. For the corner supports I removed only the rubber facing. The test fit wouldn't quite fit up, it was hitting the bottom edges of the corner supports. Rather than just removing them a 1/2" wedge was cut off the bottom of both. This allowed the clearance needed in the corners. The next test fit still had some interference and removing the rubber strip on the horizontal support solved that.

It actually fit pretty well, I clamped it into place, marked the holes, removed the bumper and drilled the mounting holes with a 1/4" drill bit. The marks matched pretty close to the indents cast into the bumper but not as good as the front. The original U shaped metal strips were reused and I installed them over the drilled holes and aligned them. Again some fitting (elongating holes) was needed here to get the outside edge strips into place. This was tough, the steel stud strips had to be reshaped to fit into the space. Installing the bumper was easy with all the removed parts. Loosely install the screws along the top and nuts on the side studs.

Starting with the two center top screws, match the bumper contour to the car and tighten the screws. Working outward and alternating side to side match contours and tighten screws to secure the bumper. The top edges could be moved by finger pressure and on the sides clamps held them flush with the body while I tightened the nuts.

Bumper is on, bolted up and fitted. Using a block and 100 grit paper I sanded down the matching edges that protruded beyond the body. Again the most challenged areas were on the sides, sticking out beyond the body about 1/8". I sanded half off the bumper and will fill the remaining 1/16" on the body to match up the contours. As in the front there are a few low spots along the edges of the bumper that need to be filled but overall a good fit.

Here is a photo of the bolted up rear bumper.
 

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Discussion Starter #46
Door Jam Prep

Sanded the door jams with 220 grit paper. Used the short block on flat surfaces and hand sanded the rest. The hinge areas done with green scotch cloth. Did the body and door frame jams, removing the door seals and old adhesives. Found an example of fish eyes in primer (photo) to show you. This was likely caused by 'Armor All' over spray into the door jam area. Fish eyes don't usually show up readily in primer, this was likely sprayed with little if any type of cleaning or preparation. This area will be sanded and cleaned repeatedly with wax & grease remover then washed with lacquer thinner. When the time comes I will mist on a couple of thin coats of primer, if the fish eyes show up again, the area will get cleaned, sanded and cleaned again.
 

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Discussion Starter #47
Headlight Covers Adjusted

Adjusting headlight covers is tedious, adjusting bolts are hard to get to and they often move during tightening. When you add the fact that there are gaps on 4 sides as well as contours on 4 sides you have your basic adjustment nightmare. The flip side of that is that nicely adjusted headlight covers look fabulous. It's worth the time and effort to get them right. You can bump edges up or down slightly (1/16" or so) with a dolly and soft hammer, use a heat gun to warm the area first. I have had to replace headlight covers that were warped, don't know how this happens but when it does there just isn't a way to adjust them to fit. Just be aware that it can happen and don't beat yourself up over it, get a replacement.
 

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Discussion Starter #50
It is a Mohawk lift (link below). This was the best quality I could find, it's hydraulic, has 10000 lb capacity but requires a 16' ceiling for the overhead transfer tubes to clear. There is an option for underground tubes. Uprights are 105" tall without the tubes.
They are not cheap, 5 years ago they were over $7k, shipped.

https://mohawklifts.com/automotive-lifts/2-post-lifts/system1/
 

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Discussion Starter #52
Yea a 9' ceiling kind of defeats the purpose of a full size lift.

I designed scissor trusses into my shop, 6-12 outside and 4-12 inside. This allowed the height without going to second story construction. I guess you could go old school and install a drive over pit like Jiffy Lube. :cheers:
 

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my old garage had a pit, but it was only for front or rear work. I have my quick lift over it now with my 69 sitting on it. I like the quick lift but it takes up floor space.

Who ever built my garage some how got around the inspectors or paid them off because instead of 16 or 24" center joints they went 32" for the ceiling. I would be better off taking off the roof and rebuilding but I am not going there.
 

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Discussion Starter #54 (Edited)
Finish the Glass

Curing time.

The car is at a milestone, it's stripped, the hinge pins/bushings have been replaced, doors adjusted, hood re-contoured and adjusted, bumpers installed and edges blocked, door jams sanded and headlights adjusted. The body is ready for filler, used to match contours (within 1/16"), fill small pits and scratches. Industry standard limit for filler is no thicker than 1/8", in this shop the limit is 1/16". If your low spot is more than 1/16" add a layer of glass mat.

Curing time on glass is longer than letting it set overnight to harden. It depends on the resin type but polyester resin will cure enough to work with in about 2 weeks. Wait until cured before any type of filler or primer is applied. This varies with temperature, humidity and oddly sunlight. The hardening of the resin is a chemical reaction, that reaction gives off gas, if covered before it's cured completely the gas will form tiny pin holes in the overlay as it escapes. Resin has a distinct odor, have you ever noticed that odor stays for several days after the resin has hardened? That odor is passed into the escaping gas from the resin as it cures.

Just about anyone who has worked with glass has heard that you can tell if the resin is cured by smell. If you can put your nose next to the new resin and can't smell it, then generally it's fully cured. The problem is this method is subjective and it's just better to allow a couple of weeks for curing. This can be accelerated by placing the repair in direct sunlight. The rays of the sun will speed up curing time, I read something about UV rays assisting a long time ago but can't remember the details. A week in the sun will cure the resin.


Filler is next so it's time for the boring subject of sanding/blocking.

This is the single area where novice painters fail the most. It isn't because they don't work hard or don't try. It's because they haven't learned sanding technique or the consequences of not adhering to it. There is much more to blocking/sanding than attaching sandpaper to a block and rubbing it on the car. Technique is important, I'll cover only the basics here as books could be written about techniques.

Given good technique a sanding block will never lie to you. It if shows you an area is low, it's low. Bring the adjacent high spots down or the low spot up. If it shows you a high spot it's high, bring it down or the adjacent low spots up. How do you know? We will be using different colors of primer and a guide coat so that high and low spots are identified. More on this later. Don't be tempted to dig in with an edge, you'll end up with a low spot. A square block on a concave surface can take off extra material at the corners, leaving shallow channels in the surface. Lighter colors tend to not show these small imperfections, darker colors and especially black will show them.

The blocks I use are 16", 11" and a 5.5". The 16" & 11" flat and curved blocks are used the most, the 11" teardrop and round blocks are used for close concave areas, the shorter blocks are used for small areas about the size of a quarter or less. Typically use the longest block that will fit onto the area your blocking. More on this coming up. The photo shows the blocks used to contour surfaces, block out wavy surfaces and remove blemishes in the surface to be painted.

The blocks pictured are made by Dura-Block, they are the best I've ever used.
 

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Discussion Starter #55
Finish the Glass (2)

As you can see from this photo, the blocks have differing shapes on their faces. Flat, curved, round, teardrop and a square block. All of these are used in differing places around the car. You notice there is no concave face on a block or a block that is curved like a bow or won't lay flat on a table. Certainly those shapes exist on almost all cars, sanding technique is used to block those areas to contour. There are some newer flexible blocks out there now that claim to allow blocking a compound curve, I cannot attest to them being easier or harder, I haven't tried one.

The sanding block has three axis and it's control can be analogous to control of an airplane. Elevation controlled by the elevators point the airplane up or down. Pitch is controlled by the ailerons and controls turn or roll. Yaw is controlled by the rudder and pitches the nose from side to side. The pivot for elevation would be at the center of the airplane horizontally sideways through the fuselage, pitch pivot would be front to back through the center of the fuselage and the yaw pivot the center of the airplane straight up and down. The elevation pivot isn't used much as the block follows the body. The other two are used extensively in blocking contours, usually both at the same time.

There will be a series of drawings associated with technique descriptions to help illustrate what is intended in the text. If you have questions please ask and I'll do my best in answering them.
 

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Discussion Starter #56
Finish the Glass (3)

Contrary to popular belief there isn't hardly any truly flat panels on a car. Most all are curved in at least one area. For instance: the C3 door is mostly flat from front to back but curved in from center to top and center to bottom. Further the rear top of the door curves up to meet the rear quarter and slightly outward at the back to meet the rear fender lip. If you place a flat block on the door parallel to the ground and block straight forward and back it will be flat front to back but cut a flat spot in the curved part of the panel. To keep both in sync slide the block sideways about 45* as you block back and forth. After a few strokes reverse the sideways motion to the other side. In this case block 45* down for a few strokes, then 45* up the other way for a few strokes. This creates a cross hatch scratch pattern in the surface that promotes adhesion and sanding this way allows flat one way and curved in the other.

The outward curve at the back of the door raises up from the flat part of the door, turn the block 45* and block straight into the curve, turn the block 45* the other way and block into the curve. Once past the curve go to a shorter block and position same as front of door for continuing to the rear edge of the door.

Photo of cross hatch below, illustration of door technique in my next post.
 

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Discussion Starter #57
Finish the Glass (4)

The rolling fender lip is another area where technique is used to keep the contours smooth and flowing. You want the curved block used to be smaller in radius than the surface your working on. Slide the block into the outward curve and roll the block outward as you slide it into the curve. The areas along the top of the rear quarter are also concave and curve. Roll the block outward toward the edge as you sand at 45*, first one way then the other. As you bring the block stop at the edge, try not to roll off the edge. More on edges later. This is the same technique used on the fender lip.

The hood has a curve that is tighter than the wide curved block. The teardrop block is used here, it's radius is smaller than the curve in the hood. Blocking at 45* bring the block into the corner, the tail of the teardrop will keep it flat on the hood. Roll the tear the other way to sand down into the curve from the top again at 45*. The center of the hood is sanded the same as the door, 45* motion and carefully rolling over the top outside edge to round and smooth it. Block up to the center from both sides but don't block over the top of the center ridge. More on edges later. What to do about the sharp reverse curve (crease) in the rear top of the front fenders. Place paper over the small corner of the teardrop, sand into the crease at 45* both directions.

By now you should be seeing a pattern emerge from the descriptions, the illustrations below should help communicate the concept. Keep the blocks as flat as you can but be aware of the contour your sanding and adjust the angles on the block to match. It isn't easy knowing what works, check your work by feel. Your eyes will lie to you, light, reflection, visual compensation between left and right eyes can lead to inconsistent results. Trust the blocks and what you can feel, you need to develop a sense for seeing the panel with your hand(s). When you see a low or rough spot, run your hand over to see what it feels like. Use a light touch and smooth motion, soon you'll be able to feel them even without seeing them. This gets harder as you block with finer grits of sandpaper, we'll be using guide coat to assist.

Illustrations below:
 

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This is really great information you're sharing. As a complete novice, I appreciate you taking the time to explain this so clearly and detailed. Thank you!
 

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Discussion Starter #59
Finish the Glass (5)

Another local question. How much downward pressure do I put on the blocks? Usually not to much, moderately light pressure is all that is needed. Enough so the paper doesn't skim over the top of the primer but not enough to distort the flatness of the block.

Notes on edges: A conscious choice needs to be made with regards edges. Back in the 1970's the custom look for car show paint was sharp edges. Straight panel lines like the center hood line on the C3 was brought up to a crisp sharp edge. The factory offering is rolled or dull edges. The thing about sharp edges is that they are not very durable, fine for a show car but not very practical for a car that sees regular use on the street. I recommend the dull or rolled edges for most applications. Techniques for both are below, plus how to make a body line arrow straight every time. Edges are an area where they have to be sanded true, sand up to the edge but not over. For things like top fender edges, blocking both sides straight will keep the line straight. For center hood or center door lines another technique is used.

Apply a piece of masking tape about 1/8" to the side of the center line. Alignment is critical, attach one end and sighting down the tape line lower it onto the surface as straight as possible. Block the opposite side toward the tape until the sandpaper just scuffs the edge of the tape. Once it does move down the line until the whole line is completed, remove the tape. Now carefully apply another piece of tape about 1/8" from the center line on the other side. Again align using line of sight. Block the opposite side until the sandpaper scuffs the tape. Remove the tape. The resulting line will be as straight as the tape. For the people who want sharp edges, you need to do this first during the 400 grit blocking and again during the 600 grit blocking. For the people who want rolled or dulled edges, do this once during the 400 grit blocking and when done gently roll the 400 block back and forth over the edge until the line has the desired contour. Do the fender edges the same way to round the sharp edge. The 600 blocking will not significantly change the line, block up to the edge from both sides and when done roll over the top only once or twice to smooth it.

Another type of edge that is often overlooked is door, hood and fender edges, these often get overlooked when cracks are filled or filler is applied. The bottom edge of the door is likely to be missed for a number of things. Edges are important too, dark colors show panel contours very noticeably, gaps seem to show up more on light colors. So make sure you clean up the edges so gaps are crisp and edges smooth. Imagine looking at a new paint job and noticing paint chips on the door edges that nobody addressed during the painting process.

You have likely heard the term 'feather edge' associated with body work and paint. It refers to a transition area between the glass/metal and applied filler, between different thicknesses of paint or between finished and unfinished surfaces. You have a low spot you want to fill, you prep and apply filler, then start blocking that to contour. As you get closer and closer to the correct contour the edges of the low spot get thinner and thinner until they are 'feather edged' seamlessly into the surrounding contour. You should not be able to feel where glass ends and filler begins. To 'feather edge' a paint repair you would be blending the new paint to match contour with the old.

Hand sanding is a must, it seems you just can't sand some of those tight places without it. When you do have to sand by hand, sand across your fingers. If you sand parallel to them it will leave deeper cuts in the substrate were your fingers apply pressure.

Tips: Clogged sandpaper can be cleared with a card file or scotch cloth. This extends the working life of the paper. In tight spaces or corners, attaching paper around the edge of the block can sometimes reach hard to sand corners. Wrapping sandpaper around a stir stick can provide a handy way to clean up edges, scoops, cowl vent grilles and any other space to narrow to get fingers in there. Use worn paper in areas where there is potential to remove to much substrate, like rolling edges.
 

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A tip on those Durablocks. I cut them into shapes or sizes needed. For instance, the long 1'x 3/4' i cut into shorter lengths, one even about 1 inch long for small spaces like around the taillight holes where it's all tiny curves. Also I cut a piece of the same block on an angle lengthwise so I could reach into tight angles like those small unreachable areas on the front spoiler.
 
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