Repair graphite chassis

[DMAT]

so essentially was doing some new holes for a stealth on my graphite chassis and my dremel decided to lose its center and go all wobly and the chassis suffered. I guess I'd be trying out how to fill the gaps back up some so the screws are better held.

[ChisaiKuso]

I've had some luck using clear, two-part epoxies.

[Supernaut]

I use 30min two part epoxy.
Crush up some charcoal from a fish tank filter or carbon fiber powder and mix with the epoxy. (If the chassis is black)

Put tape on the top side of the chassis to block the holes and fill from the bottom.
Use a toothpick to make sure there are no air bubbles in the epoxy.

Scrape off as much as you can from the bottom to minimize sanding later.
Let dry and wet sand until smooth or good enough depending on what you will use the car for.

[harvey]

That's a bummer, DMAT.
It seemed like overkill when I bought a drill press 10 years ago expressly for use on r/c cars, but the more I use it, the harder it would be to do without. Looking at some of your builds, I'm sure you wouldn't regret the purchase.

[DMAT]

So I'm finally getting to this, just posting more links to suggestions about this topic. The search funcion is preving several searches from working so if you know of another thread involving this topic that I dont find. feel free to post a link so I can read over it.

http://www.rc10talk.com/viewtopic.php?f=38&t=23442&p=232702&hilit=graphite+repair#p232702

http://www.rc10talk.com/viewtopic.php?f=35&t=22619&hilit=graphite+repair

http://www.rc10talk.com/viewtopic.php?f=38&t=21215&hilit=graphite+repair

http://www.rc10talk.com/viewtopic.php?f=35&t=17611&hilit=graphite+repair

http://www.rc10talk.com/viewtopic.php?f=38&t=16556&hilit=graphite+repair

http://www.rc10talk.com/viewtopic.php?f=38&t=13169&hilit=graphite+repair

http://www.rc10talk.com/viewtopic.php?f=38&t=543&hilit=graphite+repair

adding more links as I find them.

[DMAT]

Well, Since I'm trying to repair my chassis now. My overall goal will be to fix the holes, not fill in, and smooth up the front edge.

I've started with a good cleaning, to try and remove all the dirt. The front is starting to delaminate, i think that the right word, but either way the layers are seperating. They pulled in some water so I have the front section held tight in a vice to help force the water out the front and hopefully dry over night.

From what I've read, Next I should take some low viscosicty CA glue and fill in between the laminate layers. I'll put the front end in a polyethylene bag since CA shouldnt stick to it. Then put it all in a vice to cure for a day or two. Then I should be able to sand it down.

The other edge of the car arent seperating but they have what looks like fibrous material in them that doesnt match the black. They arent coming out easily and im tempted to sand down the edges a little to remove them.

[DMAT]

well, The front edge is a little better. I decided I'm gonna CA the entire edging of the car now.

I tried to polish it up some since the finish is really dull. It probably isnt recommended but I used mother's polish. It works surprisingly. The biggest issue is cleaning it though. It leaves a lot of oil behind so I took and washed it in dawn dish soap to get the oil out. It worked real well and now the chassis has a nice sheen to it.

so far ive been recommended liquid epoxies to fill in the deep scratches and the over sized hole. Im considering using steelstick or quicksteel epoxy at moment since its a solid compound. I should be able to make them fit the gaps I have while also molding to the shapes i need. It should particularly help with the screws since I could put a screw through it to make the shape then remove to harden. anybody else tried using these types?

[DMAT]

I'm also looking to get a new clear coat put on the chassis to give it a better look and for protection. Any DIY products you guys might recommend otherwise im gonna go to a body shop I know and have them spray it.

[jwscab]

I think you might have good luck with jb weld or something equivalent to it. It ends up being a dark gray or black, which will help blend in with the graphite.

[DMAT]

well, I bought some quick steel, a 3000 and 5000 grit pads, and some duplicolor clear coat spray. I already have other levels of sand paper so It was only those high end pads I needed.

I'll be filling in the holes with the screws already inserted and partially turned into the tranny case for alignment. I'll back the top of the chassis with some masking tape and fill from the bottom. the top half will also be backed by a nut and washer to avoiding putting the tranny case in actual contact. After all the screws are how I like, I'll give the epoxy enough time to slightly harden then back the screws out.

Will give it a day to cure. Then I'll do another polish with the 3k then 5k then another try with mothers, it did work before. After that I should be able to do a few layers of clear coat to get a nice glossy finish.

here's to a successful repair.

[DMAT]

alright, So I was able to fill the holes in with a screw in place. The nut and washer backing the top helped keep the excess putty from coming out, well, mostly that is. I was able to use the screw itself to help pack the putty in tight while it hardened. I Added a layer of CA glue over the putty too. Its drying at moment so the final cleanup will start tomorrow most likely.

The quick steel did harden a little to whitish. I'll do something about that later on.

[DMAT]

Well, I cleaned up the chassis. fixed the problem spot in the front. darkened all the holes on the chassis to match. Polished it entirely over up to 5k grit.

I've been spending most of the day spraying layer upon layer of clear coat on the chassis. This was mostly based on the advice from some body shop people to help with the deep scratches. Its gonna have to sit for a few days before the coats cure properly.

All thats left is polishing it up now

[DMAT]

So I'll be attempting to do my polishing tonight. Just curious, The highest sanding pads I have are 5k right now. Is there any reason to go higher than that? I wasnt able to see a difference between 3k and 5k.

[scr8p]

a good rubbing compound will bring 3000 scratches up just fine.

[DMAT]

Thats what I plan to do. I just have runs that need to be taken care of so I wont go straight to the compound.