Fightercat CF Cheetah Big Single build ~

[Fella1340]

Kintec can be a little slow responding to email and it may take awhile to sort out. If your in a rush and want great service order from OSE. Nobody's is even close to OSE for customer service and the speed of orders being shipped. It's not a bad idea to have a spare collet anyways. Good luck!

[mekzoid]

Tell me about my luck, Thought this year was going to be better haha.

Just bought them through OSE. Hopefully they get here quickly :S

Thanks guys!

[kfxguy]

Kintec can be a little slow responding to email and it may take awhile to sort out. If your in a rush and want great service order from OSE. Nobody's is even close to OSE for customer service and the speed of orders being shipped. It's not a bad idea to have a spare collet anyways. Good luck!

Always have a spare collet.

[mekzoid]

Jan just got in contact and is sending the replacements out, Aeromarine labeled them incorrectly as he found a few more then had the wrong sizes on the packet.
All well that ends well. Just wanna get the boat finished :P

[mekzoid]

Hey everyone! I have gotten alot done, I wont be posting photos for another couple of days as I want to clean it up a bit. All that is left is to use some 2 part foam for the hull, Would this be ok to use? http://www.ebay.com.au/itm/EXPANDING...item258ac71317
then I just need to sharpen the rudder, sharpen and balance the props, wire in the ubec and just tidy it up a bit. I think the 2 part foam that I linked to should be ok but just want to make sure.

[kfxguy]

I've done a lot of testing with the kintec foam. It works perfect. I'd recommend getting it because I know it works well. You'll need to kits of it. They are only 10 bucks a kit.

[srislash]

I've done a lot of testing with the kintec foam. It works perfect. I'd recommend getting it because I know it works well. You'll need to kits of it. They are only 10 bucks a kit.

And the reaction time on the linked foam scares me.

[kfxguy]

I've used the kintec foam in my rivercat, and my mini rivercat. I've also messed around with almost a whole kit before trusting to put it in my boat. I'm telling you, you best bet is to get the kintec stuff. It does not expand more when it gets wet. Here's my method.

Mix up 20 grams (10 and 10 of each) and pour into the tip of the boat. Then tilt the hull to drain the foam toward the rear of the hull. It will build up on the floor. Have a flashlight handy so you can see where it's going and make it go where you want. You'll see what I mean. It wouldn't hurt to mix some up and pour it into a V shaped piece of cardboard to get an idea of what your working with. It does start expanding fairly quick and gets to where it don't move kinda quick too. It will work perfect if you know what your up against so I do highly recommend a practice pour with anything you use. You get this stuff and you won't be sorry.

[kfxguy]

And the reaction time on the linked foam scares me.

I agree. I wouldn't use that stuff in the link. That's too fast.

[Fella1340]

I just had to add another option. A carefully made bulkhead or two and some foam cut to fit will give you a stronger end result. It's more work and very tedious but I just can't bring myself to pour that crazy foam into one of my boats. If you do use it follow these guys instructions exactly. Pouring too much or rushing the job can do some serious damage. Srislash and kfxguy know what they are talking about so ask every and any question you have before you start. This is definitely an area where there are no stupid questions.
I would consider using some chopped carbon fiber and milled fiberglass mixed with resin in the tips and center section before going with Foam as it won't help your seams out. I wonder if it actually increases the chance of a split seam or opening up across the front in a crash. The foams expansion puts pressure on the hull everywhere its poured in. The stuff scares me. You really want to make sure your seams and across the front of the boat is reinforced before pouring the foam in. I am new to rc boats but I think my thoughts on this are worth considering. Considering all options before you go ahead is a good idea. Some guys swear by using foam and others not so much. Good luck! I am looking forward to seeing your progress.

[jj2003]

There is coremat all in the front so no need for epoxy. Wont be doing 2 part as I wont lose the boat anyway, I use the boats in a large wading pool about 200 meters long and its only 2 foot deep max. I also have a fear that if a seem splits or something cracks, the 2 part will expand as it always does and make it near impossible to fix the hull

Hi mekzoid! Sorry for chiming in so late. Great stuff foam has 2 types available. The black can for full expansion, and a blue can, low expansion rate. Despite so many people stating that it's bad or if it's open or closed cell, I think many of the doubters have not tried it in fear of over expansion. The blue low expansion works like a charm. I can float on my 45" Speedfreek after filling it with water. If you have to trim some off, a long blade exacto knife does the trick and leaves it nice a smooth. If your fear of it being open or closed cell worries you about water absorption, you can "close"it with a thin layer of epoxy. I have done several test's with the stuff. I sprayed some out on a piece of cardboard, cut it into multiple pieces and threw it in the tub. Tried to submerge it and no go. Let it sit in the water for a period of time to see if it would absorb water. No go. I still don't understand all the hub-bub of the differences between the two. If you read the chemicals involved they are the same stuff as part a and part b mixes available from various places. The only difference I see is the amount you can get for the price. Even the quality expansion foam's available from various suppliers is made of the same chemicals. If you already did the foam then maybe just something to think about for your next build. JJ

[kfxguy]

Hi mekzoid! Sorry for chiming in so late. Great stuff foam has 2 types available. The black can for full expansion, and a blue can, low expansion rate. Despite so many people stating that it's bad or if it's open or closed cell, I think many of the doubters have not tried it in fear of over expansion. The blue low expansion works like a charm. I can float on my 45" Speedfreek after filling it with water. If you have to trim some off, a long blade exacto knife does the trick and leaves it nice a smooth. If your fear of it being open or closed cell worries you about water absorption, you can "close"it with a thin layer of epoxy. I have done several test's with the stuff. I sprayed some out on a piece of cardboard, cut it into multiple pieces and threw it in the tub. Tried to submerge it and no go. Let it sit in the water for a period of time to see if it would absorb water. No go. I still don't understand all the hub-bub of the differences between the two. If you read the chemicals involved they are the same stuff as part a and part b mixes available from various places. The only difference I see is the amount you can get for the price. Even the quality expansion foam's available from various suppliers is made of the same chemicals. If you already did the foam then maybe just something to think about for your next build. JJ

(Sorry in advance) DO NOT LISTEN TO THE ABOVE! I have wasted two cans of both kinds experimenting with it. As much as I wanted it to work because it's cheap, easy to find, and easy to fool with....the fact is that it crap and will funk your boat up. Don't believe I did a lot of messing with it? Here's some proof...had to throw a brand new hull in the trash because of it. Here you go...

This is after 24 hrs...I cut it open and it still hasn't finished curing



Here is a shockwave 26 hull before foam.....



Same exact hull after foam and waiting about 3 or 4 days

[Fella1340]

Get the proper stuff if your going to use it!

[kfxguy]

I mean no offense to jj, it may work for you and that's great. I already know how go "make" it work but it's too much crap to deal with and chance in my opinion. I don't feel like spending days on getting the foam correct in my hulls. I'm starting on a new build tonight and I have plenty of kintec foam. It just works.....and no drama with it. When the outside is cured, so is the inside. On the spray can stuff, it air cures. The middle that get little to no air takes a long time to cure. I've cut open the kintec foam and because it's a chemical cure, it was cured throughout. I guess I'd rather back safe than sorry. Like I said, no offense or anything meant....I'm just trying to keep anyone from messing up their hull. It may work for you because you may know how to mess with it, but just spraying it out the can and into your hull will result in some undesired effects if you don't know what your doing.

[jj2003]

(Sorry in advance) DO NOT LISTEN TO THE ABOVE! I have wasted two cans of both kinds experimenting with it. As much as I wanted it to work because it's cheap, easy to find, and easy to fool with....the fact is that it crap and will funk your boat up. Don't believe I did a lot of messing with it? Here's some proof...had to throw a brand new hull in the trash because of it. Here you go.

I can understand you pain kfxguy. I have seen both sides to it as well. And to each his own opinion. The 2 part system acts the same way when to much is applied at once. It needs air to cure and room to expand(even if it is low expansion rate). I know there are experienced boat builders on here as well who don't like the unprofessional approach to it but if used correctly it work's out fine. Some dont believe in it at all and strictly rely on pool noodles. If you were to take a survey, many would say they had the same experience and would never do it again, but some would also approach it's application differently as well, trying to get it to work properly, especially if your on a budget. Sure the 2 part system is nice and you can control the expansion rate as well. They also make different types of foam too. Some have different lb density ratings as well as chemical make-up. But you have to remember do not flood the entire compartment with the mix and be sure to apply in layers as to allow for air to cure the mix. If there is no air, there is no cure.

mekzoid, Do what you feel most comfortable with and with recommendations as well and by no means take anyone's word that this is the "s**t". Even mine. All of our experiences are different and never exactly the same, and there is a learning curve. If that weren't the case, we would all have the same hull's going just as fast as the next guy. Good luck and looking forward to your experience!