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Can it be bondo times now? (read: stupid caturday compositional risk). Time for another custom fender update, and as you may have guessed it’s all about bondo!

What do you say instead of me blabbing about it, we just get right into it?

Lots and lots of bondo. Yummy! This stuff hardens pretty quick, and is startlingly easy to work with. Maybe it’s normal, and we’re just used to how much of a pain fiberglass is to work with, but bondo was a very nice change of pace. As you can see, we were very liberal with it (and we had to be, better safe than sorry). We figured we’d just start thick and sand down. So here we are. We used some graters to do the really rough and excess ridges, but for the most part we used various sanding instruments and eventually moved to sponges with finer grits.

Progress…
 

More Progress!!
 

Almost done with the grater
 


Honestly, this test fit was completely unnecessary. It really didn’t help us do anything except see what it looked like…sort of. I mean, the fender wasn’t even cut, it was BARELY sanded down…but we just couldn’t help ourselves. I think this was us taking a break because our fingers had cramps. Now for a time lapse, because the in-between-shots are even more boring than the pictures I’m already forcing on you.


First coat of bondo relatively complete.
 

As you can see, there are lots of bubbles, and the spine is very faint.
 

Once you start using Bondo, I propose that you are never really done with Bondo. So far I have been right… So we needed to make the spine more prominent. Since none of you can see where we’re cutting the fender, you’ll have to wait and see the end result, but we know the fender is going to be very short, just barely beyond the passenger seat in fact. If we’re going to make a spine it needs to be very prominent, or else risk looking simply like a dent or imperfect bend. We took a strip of metal mesh, 4 inches wide by 14 inches long, (the same mesh we used on the interior reinforcement) and bent it width wise in half to make a V shape. Upside down and placed over the faint spine and completely filled and surrounded it with bondo. Here are the preliminary results! If you enlarge it, you can see the mesh poking out the end (which is fine). Not only can we trim the metal later, but we’re trimming the whole fender so the sloppiness of the edge is really of no consequence.

 
 

Honestly, who needs a DSLR when you have floodlights? This dramatic lighting was unintentional but it definitely shows how much more drastic the spine has become. This experience has really changed how I see bodywork. I no longer see something like this as ugly, it’s simply not beautiful yet. You also might notice the whole fender is a bit messy. We attempted to fill in a lot of bigger bubbles with the heavyweight bondo. Something I recommend doing only once, but since we didn’t learn about light weight bondo for bubbles we ended up doing this several times as you will see in the pictures to come.

Initial Bondo is nearly complete!
 


We finished the prime sanding, up to 220. This is nowhere near complete, but it’s finally starting to look like it’s heading somewhere. Just a teaser, these are the first cut lines we drew out. Don’t mind the stripes on the sides, I’ll explain those in the next update

Tags: custom, fender, motorcycle

So the shell was made. It was not very strong, and far from road worthy. First, we had to reinforce it. Since we made the fiberglass fender on the outside of the current fender, it’s safe to presume that the fiberglass copy is just a hair larger than what it should be. For that reason, we decided to reinforce on the inside.

We skipped a few steps without photographing, but basically we trimmed all the excess fiberglass strands to clean it up and then cut all the edges, and sanded them to make it crisper, otherwise it would be more like a case for the current fender. This still isn’t the final shape, but it’s getting closer.

The entire inside was sanded to remove bubbles, soft spots, unevenness etc. and then we cut fiberglass matting exact to fit. On top of the fiberglass you can kind of see it in the image, we used an aluminum screen door sheet to create a mesh support matrix, and when it dried it really, REALLY strengthened the fender.

Now, to apply even pressure to the entire inside of the fender while it was curing (because it kept peeling off) we use a trash bag filled with water, like a gigantic water balloon. If I were to do it again, I’d find a different way to do it, this was NOT desirable. If you decide to pursue this method, know that we use THREE contractor grade bags to make absolutely certain it didn’t break and ruin the entire thing.

You’ll note in the picture below that there are lots of clamps around the fender. They served two purposes, one was to line the edge and make sure the edges adhered perfectly, and the longer ones going across the width of the fender…well, this is why I’d try to find a different way to do this next time. When we put the super-water-balloon inside the fender, it bowed out the shape quite a bit. We used the long pipe clamps to compress the sides and return it back to it’s normal size while curing. It worked out okay for us, but I don’t think I’d risk it, because there’s a LOT of places to screw up, and frankly we did mess up a large portion of it. Luckily, the portion we messed up was being cut off anyway.

Rise and shine! After siphoning out the water VERY carefully (there were several GALLONS of water inside, and lifting was too risky) we used a blow drier to get out the last little bits of moisture and then let it cure for a bit longer.

Bondo time!

Tags: custom, fender, motorcycle

This was much more enjoyable, and felt like it would produce better results. We started the process by using the current Jackpot fender as a base. This was the key different, most of the other stuff was relatively similar. We used saran wrap to completely mask off the fender, and painter’s tape to get the seams. On top of the clear saran wrap we used spray adhesive to hold long strand fiberglass mat in place. We covered the entire fender with the fiberglass matting, the spray adhesive was only to make the next step easier. We wrapped the entire fender in a T-shirt, and to stretch it underneath we bunched up as much as we could and stapled it:

We knew this fender was going to be much shorter than the current one, so we weren’t concerned with making it all the way to the edge, just well over our cutting area:

More or less ready for tons and tons of resin to solidify the whole thing:

Because of how quickly resin becomes gelatinous we had to make it in batches. Approximately 1 cup of resin at a time. If the resin becomes really stringy and semi-jello like, it becomes VERY difficult to work with, but that’s only because of the long strand fiberglass. It grabs it and really moves the stuff around, sometimes clearing entire spots with a single swipe by accident. So, after two batches of resin:

After all the resin is done (for the first coat, anyways) and ready to dry for a looong time. This is the longest drying period, because the original fender is still underneath, which means the saran wrap is still underneath, and once the resin seals off on the outside, the inside takes a tremendously long time to fully cure. We ended up waiting 2 full days and it still wasn’t done, but it was hard enough that we could remove it delicately and let it dry without the backbone.

Still glossy in the next few pictures, but time did pass in between the shots. You can see what I mean about the drying just not happening with the fender still inside:



Finally getting dry to the touch!!

Here are the version 1 and version 2 (alpha) fenders:

The next step is to trim up the shell and start reinforcing it, after all it was still going to be functional as a fully supportive bracket for a passenger seat and a passenger.

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On to reinforcing!

Tags: custom, fender, motorcycle