Expandable Foam Help

[chefmarkt69]

Hi I have never used expandable foam and was wondering if anyone could give me some pointers on how to use it. I am going to be filling two large nose cones. One is a Loc 5.5" and the other is a Loc 7.5", thank you for the help.
Mark

 

[bill2654]

I have used it with a couple 4" and 5" nose cones. I also used it in a LOC 4" V2 tail cone. With the V2 I tacked my fins in place then filled the tail cone with foam and they came out rock solid. Then I could use minimal outer fillits. One tip I can give you it is hard to estimate how much is needed to fill different size spaces so I tended to use too little and ended up having to make two pours. One other thing is you need to give it a place to over flow in case you over fill. It will expand or slightly bulge what ever your filling if you use too much. It can be messy and a pain to clean up so it does take a little practice. It is tricky so I tend to use too little rather than too much. Also it gets hot when it starts to kick so I would set my nose cone in some water to keep it cool while setting. Hope this helps.

 

[new2hpr]

That, and make sure you're using the 2-part epoxy foam, not the stuff in the spray can from the hardware store!

Keep the pours small and you won't have an issue. Too much and you'll be cleaning bubblegum consistency crud off everything!

Don't ask how I know.

 

[chefmarkt69]

Thank you Bill I will let you know how it goes.

 

[chefmarkt69]

Thank you and yes I almost used the stuff in the can but then thought wait a minute let me ask first.

 

[blackjack2564]

Make sure to drill/cut a large enough hole to easily pour the foam into. At least 1/2in. too small the hole will skim over and prevent further pouring till poked out.[this stuff is like trying to pour honey]

Plastic cones your size will definitely generate enough heat from the pour to distort them. Place the cone in a container of water to dissipate the heat. I use a small waste basket. I use a brick to keep it from tipping over, no need to fill with water, just enough to cover area being foamed. If nc wants to float use a board set on top of WB to wedge cone in corner so it can't tip.

I don't know why you are foaming them so I will offer this: [I have foamed dozens all the way up to 7.5 in Glass]
Just to add strength.....
You can fill the tip end of cone about 1/3 full, then after cure add foam packing peanuts or balled up newspaper to about the shoulder, then continue adding more foam to finish off. This will save alot of weight and more importantly foam. It will take more than 1 bottle set [8oz per bottle-2 per set=16oz tot] to fill a large 7.5 in cone. I did it with one using peanuts . You can guess how I figured this out....my first cone. Lol This enough to make them strong with out filling all the way.

Second if you get any where you don't want it. DON'T try and wipe it off....wait till it cures, it will come off much easier by scraping with a blade and sanding the residue.

Finally when mixing, it should look like coffee with cream if done correctly. You will have 30-45 seconds at 75-80 degrees ambient temp. before the reaction begins.....cooler longer....hotter less time. So mix it as fast & thoroughly as you can . It can take between 15-30 minutes for it to harden.

Do the smaller cone first to get the hang of it. Good luck and were old clothes you don't care about. This stuff doesn't come off! LOL:smile:

 

[chefmarkt69]

Thank you Jim, The reason I am adding foam to them is that I have some nose cone weight in the tip of the cones. Which is the metal weight mixed with liquid nails to hold it in. I thought by adding the foam then it would prevent that wieght from coming lose. Just a safety net thats all. But I am open to some more ideas if you have any. It seemed that this would be the best way to secure that weight in place thats all.

 

[Wayco]

Thank you Jim, The reason I am adding foam to them is that I have some nose cone weight in the tip of the cones. Which is the metal weight mixed with liquid nails to hold it in. I thought by adding the foam then it would prevent that wieght from coming lose. Just a safety net thats all. But I am open to some more ideas if you have any. It seemed that this would be the best way to secure that weight in place thats all.

We did this last weekend to add an ounce of weight to a Leviathan. The foam we used was Public Missiles Adjustable density two part foam. By adding one to four drops of water per oz. of mix, you can make it dense or light. We got ours from What's up Hobbies, but you can get it direct from the source here:
https://www.publicmissiles.com/secure/components.asp?groupid=19

.

 

[chefmarkt69]

Thank you Wayco that seems to be a good product. Have a good night I will keep everyone posted on this thread of the out come.

 

[Marc_G]

One word of caution: WEAR PROPER PROTECTION PARTICULARLY GOGGLES. If this stuff gets in your eyes it is a major problem.

 

[chefmarkt69]

Thank you marc, I try to wear the proper PPE, the reminder is always a good thing. Have a good day.
Mark

 

[CarVac]

One word of caution: WEAR PROPER PROTECTION PARTICULARLY GOGGLES. If this stuff gets in your eyes it is a major problem.

How on earth would it get in your eyes? Though yes, it would be a major problem in the eyes.

Aside from that, in my experience with GLR Megafoam, big syringes are a boon for injecting: you pour in one part, then the other, then mix it up with a popsicle stick, and then you put in the plunger and inject through a hole. Not really applicable for nosecones, but it's nice to know.

 

[AZ_Ron]

Just wanted to confirm a few comments in this thread!!! Make sure you wear crappy clothes... I've lost count of the 'good' shirts that have become work shirts because of 2-part foam!
Once it's on your clothes, it's never, EVER coming out!
I foamed the fins into my 16" Mega-Diablo with 4lb/cf foam about 5 years ago for the LDRS in Jean, NV.
I wound up foaming in late June... I've never seen foam kick that fast. I basically poured the parts in the mixing cup, then stood over the
aft end of the rocket, mixed and dumped. Crazy fast kick off when it's 115f outside!
I've been using this stuff since 1998. I've probably used most of the brands out there and to be honest have found little difference. Only real
difference seems to be the weight, ie 1, 2, 4, 6, 7, 10lbs/cubic foot.
I've never used about 4lb/cf. 1lb/cf in the small stuff, 2lb/cf in just about everything else. Used 4lb/cf in the Mega-Diablo, as it was kind of an
experiment to see if it would work well on something that big. Worked great!! 16" Airframe, 6" MMT. I tacked the fins in with some 5-minute epoxy,
which in that heat was almost like think CA! Then did the foam. No fillets, no 'glass or reinforcement at all.
I did my Level 3 cert at LDRS in Jean with a 17,000Ns AMW 'N-2800', and then flew it again the following year on an 'O' motor made by James
Russell. Two perfect flights. I sold the rocket to a buddy of mine, and just before he was getting it on the pad, a fin snapped off of it. (Long Story,
but if you truck a large, heavy (150lb) rocket to the pads, put something under it to support it) I got the chance to see the rocket before
he repaired it. The fin snapped off about 1" outside of the airframe. Foamed in part was still solid as a rock.

I use the 2-part foam in the fin cans because I'm lazy! Makes building larger birds very fast!
Sorry this went a bit off track... I tend to ramble...

Cheers!

Ron

 

[AZ_Ron]

Oh, in case anyone is interested, the Mega-Diablo took about 3 gallons of foam!