JB Weld set up

[kfxguy]

What are you using to dye the epoxy?

I've done some experimenting with it because I'd like it to be black in just one step, however I have not accomplished that yet.

Here's what I've found:

Epoxy dye: it'll dye it but it makes it rubbery. It never really gets hard like it normally would. Not good on a motor mount because it didn't seem to grab as well either.

Graphite: it takes a lot of powder to make it turn black. It does not feel as strong either.

For the sake of you guys, I'm going to try something else tonight. I got a can of finer graphite powder from west systems and I'm going to try it.


Normally what I do is once the jb weld is cured, I scuff it up and put a nice smooth coating of epoxy that I dyed black with epoxy dye. It comes out flawless when I do this. It's another step but it comes out how I want it. I honestly don't trust west systems (it is some badass epoxy don't get me wrong) for motor mounts in a single. There's a lot of stress on it and I know jb weld will hold. There's some top record holders here on this forum that use it too, if it's good enough for them, it's good enough for me.


Hahaha not sure why/how I got off track with expressing jb welds goodness lol

[Newboater]

Can you paint the JB weld? I was thinking of painting it black.

[kfxguy]

Can you paint the JB weld? I was thinking of painting it black.

I don't see why not.

[ray schrauwen]

Prep first like any surface to paint.

[kfxguy]

Experiment tonight for you guys. From left to right:

1) jb weld with graphite. It did not like to mix, was hard so work with and took a lot to get it almost black. Do not recommend. You can tell it's clumpy in the photo.

2) Jb weld with nothing added.

3) jb weld with 5 drops of super concentrated black epoxy dye. This dye goes a long way. Two drops will turn twice the amount of clear epoxy black vs the amount of jb weld. It just requires too much to turn the jb weld black.

Tomorrow I'll test the hardness of each one and post back.

[Newboater]

I would think graphite being a lubricant would effect the strength, probably best choice is to leave it grey or just paint it. Curious about the result though.

[kfxguy]

I would think graphite being a lubricant would effect the strength, probably best choice is to leave it grey or just paint it. Curious about the result though.

Yes I thought that too. However, I use it in clear epoxy with great results. I think it's because it's actually a powder instead of a liquid. I'll post the results/impressions on the perceived strength tonight.

[Tamelesstgr]

Thanks for doing this, I really struggled with messy epoxy lines on my 32 mono, would like to do a better job on my next build.

[kfxguy]

Ok I have some info for you guys. The jb that I used ropy dye, no. Not going to work unless you need rubbery epoxy. It was completely flexible. I could dig my nail in it and pull on it and it would spring back.

The graphite dyed jb weld was just as stiff and strong (perceived when I snapped them both in half) and the regular jb. Maybe you could experiment with it and just tint it dark grey and not try to get it black like I did and it might be a decent method.

[kfxguy]

Here's some pics of the epoxy lines. I'll be posting them in my 34" mono build thread also.

[T.S.Davis]

It's funny how everyone has different experiences. I've never had any luck with JB Weld. In fairness though, I haven't tried it since the plastic hull days. If you have something that's working go for it.

Not looking to sidetrack ya's but wanted to share.

Tom C. from our club turned me on to a different approach. He's been modifying his mounts for easy in and out so that in event of a motor hiccup he can get a new one in the boat in under 5 minutes. It can be the difference for us with as much as we deal with on race days around here.

He doesn't use the black pieces of carbon plate that Travis has JB'd in. Basically the face plate and tail ring is attached to two piece of angle that run length wise. Those angle pieces are then bolted to rails that are epoxied to the hull. In a mono the rails tie the transom, the bottom, and the motor mount together. Zero hull twist from motor torque. The best part is that you can have the whole assembly in your hand in under a minute. Pretty sure his are modular so to speak. Each boat is the same so he may well have a spare motor already in a mount so that he could drop a whole assembly right back in. No fiddling with motor screws between heats. He can literally swap a motor and still call three heats before he has to run again.

[kfxguy]

It's funny how everyone has different experiences. I've never had any luck with JB Weld. In fairness though, I haven't tried it since the plastic hull days. If you have something that's working go for it.

Not looking to sidetrack ya's but wanted to share.

Tom C. from our club turned me on to a different approach. He's been modifying his mounts for easy in and out so that in event of a motor hiccup he can get a new one in the boat in under 5 minutes. It can be the difference for us with as much as we deal with on race days around here.

He doesn't use the black pieces of carbon plate that Travis has JB'd in. Basically the face plate and tail ring is attached to two piece of angle that run length wise. Those angle pieces are then bolted to rails that are epoxied to the hull. In a mono the rails tie the transom, the bottom, and the motor mount together. Zero hull twist from motor torque. The best part is that you can have the whole assembly in your hand in under a minute. Pretty sure his are modular so to speak. Each boat is the same so he may well have a spare motor already in a mount so that he could drop a whole assembly right back in. No fiddling with motor screws between heats. He can literally swap a motor and still call three heats before he has to run again.

Interesting. I'm all for better ways of doing things. Got any pics to illustrate?

[T.S.Davis]

haha Not on me. I'll have to get something. I have one at the house I did that way in a sporty. I'll snap a pic later.

[Newboater]

Doesn't Traxxas have a similar concept. I think they have a modular frame that allows you to pull motor, esc ,radio and servo out all in one unit. same idea right

[kfxguy]

Doesn't Traxxas have a similar concept. I think they have a modular frame that allows you to pull motor, esc ,radio and servo out all in one unit. same idea right

Awesome. Hopefully it's something better than what I'm using. $30 each mount is getting expensive. I have heard there's a new mount coming to market hopefully soon.