When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Glass the back first. V out the cracks. Start narrow with the glass mats, then each layer go a little larger. It's better not to cut the glass strips with scissors. Pull it apart.
I wanted to give an update of my progress. I went ahead and attempted to fix the first crack. See the pics below. I applied new fiberglass mat to the back and front of the fender, and then sanded the front down to match the body contour. As you can see in the pic, I did uncover a few bubbles with the sanding. My next step would be to apply VPA over the top of the fix to fill in any of the pinholes created during sanding, correct?
My concern is the interface of the two layers at the crack itself. It may be hard to tell in the pics, but I think I have a small bubble or two in the crack. What danger, if any do those pose?
Outstanding work! Keep that up and you can turn pro!
The pinholes are part and parcel to the process. Take a sharp pick and gently rough up the sides and bottoms (don’t spend more than a minute) to provide a surface for the filler to adhere to.
Nothing wrong with the VPA but you can use any quality catalyzed filler. Be sure to work it into the holes as you spread it out.
Update:
Here's a second crack I worked over the last couple days. I think it repaired a little better than the first crack that I showed previously. Still have a bit of sanding to do before I top it with VPA and do the final contouring. Overall I'm pleased and think it'll hold.
I'd like to tackle the front area next, but it's had some serious work done in the past already and I'm not sure where I should pick up. Couple things, do I grind all that previous work away and attempt to make all new repairs. Whatever they repaired it with, it looks like its just resin, epoxy, or something. Unless I'm mistaken, I don't think they applied to fiberglass mat. You can just make out on the top of the car, looking through the repair, and pretty substantial crack that they applied the resin over. I've got a picture from the back side you can see. Additionally, the actual crack on the side of the lip sits right on top of that bonding strap on the inside, So I can't actually get to the crack from the inside. It does look like the bonding strip itself has come loose slightly. I don't really know how to tackle this repair.
Do I grind all previous repairs away and start completely fresh?
Where the crack is on the bonding strap, do I just attempt to repair it from the topside only?
This is the top of the car. You can see the backside of the big crack they applied the resin over.
The resin only areas will need to be redone as there is little strength due to lack of fibers. The good news is you have developed a good understanding of what is involved in making a proper repair.
As you tackle larger areas, you might consider making a mold of the area as doing so will minimize a lot of sanding. You can also use techniques such as a piece of cardboard wrapped in tinfoil to bridge open areas. No one right or wrong way, just applying some common sense creative problem solving.
As for the bonding straps, they are fiberglass as well so no issue glassing over one.
and try not to work straight over your head. i had to reattach the deck on my boat from below it. resin dripping on your face and in your hair is very unpleasant...
Quick question regarding the lip edge of the inside of the fender (see pic). I had to grind away more than I'd like away due to the crack. You can see it's a pretty good trough of fiberglass along the edge I had to take off. What's the best way to fix that edge line. Do I need to apply more glass matting and build it up with multiple layers, that seems difficult based on the thin edge line. Can I just build it up with VPA and shape it the best i can?
Using the same guidance as before, grind out a shallow “V” on the backside (inside) and lay up a couple layers to span the damaged area. Then feather the outside and layup 2 layers. If you are comfortable with the process, you could do this in one step.
Stay patient, don’t rush it. I know it’s tempting to slap on a layer of stucco (my term for Bondo!) but always keep in mind that the strength of the repair lies in the fiberglass. The purpose of the filler is to address minor imperfections.
You are a quick learn! Keep up the great work. Others are learning a lot from what you are doing so thanks for sharing.
take a piece of plastic can lid or bondo spreader cut it down to size and clamp it to the bottom of the lip as a half`*** mold to keep the glass you lay up there in place. and be careful. if you get too good at this, dudes gonna be bringing you their cars. neighbors may get irate you running a vette glass shop in a residential zone...
Last edited by derekderek; Jan 8, 2022 at 06:01 PM.
Update: I added multiple layers of mat to build the edge line back up. Overall, i think it went pretty well. I should be able to top it with VPA to get it perfectly smooth.
As you can tell, i obviously haven't put a lot of thought into blending the back of the fender to try and hide the repairs. Not sure I'll do much because I don't want to take off too much of the repair. I want the structural support.
Unless you are planning on entering concours competitions, I would not spend any time on the backside. As you correctly point out, the more you grind away the less strength you will have.
It appears you butted the new repair against the ends of the existing lip where the piece of it was missing. There is very little strength where the new material is against the butt ends of the existing lip and that's where it will most likely start to crack again. Especially the right side where it appears to be butted into the flat square end of the old. Left has a bit of step to it that spreads the joint over a larger area.
The stuff on the back side might strengthen it enough it'll hold. If you haven't done the outside, grind that face as well as the inside of that lip. You want it to tapered over a 1-2 width on each side with most of the old gone at the new to old joint. Then fiberglass it by building it up with progressively bigger pieces of mat.
I should have posted this earlier in my first response, If you haven't yet go to YouTube and look up fiberglass boat repairs. There are some good videos showing how to do it.
Also, give the repair a few good whacks with the palm of your hand. Better to have it crack again and need to be re-repaired now vs it cracking after the paint is on the car and you've started driving it again. If an original fender can take a smack from your hand just fine without damage then any repairs should be able to as well or they're not strong enough.
It appears you butted the new repair against the ends of the existing lip where the piece of it was missing. There is very little strength where the new material is against the butt ends of the existing lip and that's where it will most likely start to crack again. Especially the right side where it appears to be butted into the flat square end of the old. Left has a bit of step to it that spreads the joint over a larger area.
The stuff on the back side might strengthen it enough it'll hold. If you haven't done the outside, grind that face as well as the inside of that lip. You want it to tapered over a 1-2 width on each side with most of the old gone at the new to old joint. Then fiberglass it by building it up with progressively bigger pieces of mat.
Hi, thanks for the reply. I actually did end up tapering the lip edges after i took those pics that I posted. Then i built it up with increasingly larger pieces of mat.
I do like the idea of tapping the panel worh my palm to see if the repairs hold. I'd rather find out now vs later.
Hi, thanks for the reply. I actually did end up tapering the lip edges after i took those pics that I posted. Then i built it up with increasingly larger pieces of mat.
That's excellent. If you look at pictures of failed repairs it's often because the repair wasn't blended into original panel over a wide enough area.
I went ahead and attempted to work the more major repair area on the front passenger side of the car. I have pics in previous posts. I ground out all the previous resin only repair and could tell there was some major cracking underneath it that had to be cleared out. As you can see in the pic, it's essentially opened up to the bonding strip on the back side. The problem is, it's basically a circular crack around the perimeter of the circle now, and you can see it's a nickel width gap between the fender and the bonding strap. I'm not sure the best way to tackle this. I have very limited access from the backside of the fender. Do I build up a couple layers of mat on the middle circular part first until it's close to the fender thickness, and then apply much larger patches to actually cover the entire perimeter crack? With the bonding strap not perfectly adhered flush to the panel from the backside, the gap worries me that it won't be a strong repair.
You clearly don’t want to have any voids in the repaired area so I would recommend you first grind/sand back to remove all traces of the void. Then, as you have indicated, cut a series of patch pieces of matte that will progressively “fill” the damaged area. Just as you have done with the other crack, you always want to taper down the edges of the repaired area to ensure you have “bridged” the repair, tying into the original panel by at least an inch to one and a half inch.
I am not familiar with the details of the rubber bumper support but I surmise that removing the support would give you what you need to access the backside of the repair area.
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Slideshow: A Jaguar designer's personal project imagines what a modern front-engined Corvette might look like if Chevrolet revisited the golden age of the Stingray.
