4th December 2016, 04:40 PM
Fire Blankets around launch pads
Hi, our club is looking for recommendations for types of fire blankets to serve as ground cover around launch pads, and where to buy them. We have some old yellow ones now that are about 6 ft x 6 ft that are pretty worn out. We launch mid- and high-power rockets on grassy fields and need to protect the grass.
4th December 2016, 05:01 PM
8' x 8' welding blanket from HF?
Originally Posted by clarinet
Last edited by dhbarr; 4th December 2016 at 09:42 PM.
4th December 2016, 09:34 PM
Agreed, the 8' x 8' welding blankets from Harbor Freight are not a bad option. Of course, without good blast deflectors under the rockets, you'll burn up the blankets in no time (we now have better HPR launch pads and better cooperation in using the deflectors in the MMMSC - now we need more new blankets).
Originally Posted by dhbarr
I'm sure there are better quality blankets available but would likely be much pricier; I'd be interested in hearing from those who are using real industrial blankets.
4th December 2016, 09:45 PM
Dino Chutes makes a 5'x5' 1/8" Nomex blanket. Never seen one in person, though.
Originally Posted by KennB
Last edited by dhbarr; 4th December 2016 at 10:29 PM.
4th December 2016, 10:23 PM
Thanks for the mention. Ours are about the thickest I've seen as compared to others that are much thinner Nomex. We get the fabric made for us at this thickness and they last a long time. They're also slightly absorbent so that you can soak them with water prior to use. And the grommets are industrial spurred grommets that are very hard to accidently pull out.
I forgot the name of the club, but whatever club launches in northeastern Colorado in the grassland area is very pleased with this product.
5th December 2016, 03:12 AM
I use a welding blanket from Northern Tool and Equipment around my launch tower. You can't get a much closer blast than they get there, and they hold up pretty well.
So much of my rocket building time has been diverted toward my "other hobby": Race Timing
13th December 2016, 01:25 AM
Welding blankets hold up okay. We prefer old aluminum signs under the pads. Those hold up much better. We put welding blankets under a O motor - the nozzle was ~48" from the ground. We only found small remnants of the welding blanket.
13th December 2016, 03:06 AM
Had 6x4 welding blanket on the ground under a CTI 75 mm M1300 and it destroyed the blanket. I won't be using a welding blanket as ground cover without a metal blast deflector again!
Originally Posted by AlphaHybrids
TRA 10756 L3
CAR S922 L4, RSO
13th December 2016, 05:38 PM
Thanks for the comments. My understanding of fire blankets, Nomex fabrics, and Kevlar is that they are flame resistant but can burn under relatively severe conditions. They are based on organic polymers that are resistant to burning but are ultimately combustible. Our club's HPR pad does have a metal blast deflector but we also want some good new fire blankets to cover the ground area.
13th December 2016, 08:35 PM
Originally Posted by rms
You still need a blast deflector. Even a BP motor exhaust plume impingement will blow through a fiberglass welding blanket........
CMASS, MMMSC, Tech Officer, NAR S&T
BOD URRG, MRSI, MMMSC
L2 NAR 78096 TRA 14588
CAP 536940 NER-MA-019 CDC, AEO
13th December 2016, 08:57 PM
We had four stop signs directly under the pad, with the blanket under them. The flame lifted the stop signs and then toasted everything.
Sometime I want to get a 10 gallon pressurized tank hooked to 3 spray sprinklers around the pad. Turn on the sprinklers 15 seconds before firing and then let it exhaust the water. The sprinklers have a flow rate of 3 GPM each, 10 GPM total. Put 5 gallons of water in a tank and you have 30 seconds of fire coverage.
14th December 2016, 01:42 AM
Plus, what a great steam plume.
14th December 2016, 01:55 AM
Nope no D'ohs, we have one hp launch per year and the CAR safety code requires some sort of deflector to keep motor flame from contacting the ground. Was either the blanket or not fly the rocket as there wasn't a deflector on the launch pad.
Originally Posted by bobkrech
However, I will have something different than a welding blanket for next launch!
TRA 10756 L3
CAR S922 L4, RSO
14th December 2016, 02:44 AM
I'm considering fabbing a steel cone that will fit over my jawstand upright and rest on the three legs just off the ground. If it's worth doing, it's worth overdoing :-)
Originally Posted by rms
14th December 2016, 03:25 AM
Used harrow discs make great blast deflectors. These pictured will fit on a 1010 rail with no modification and can be ground out to fit a 1515 rail.
The MMMSC pad manager has modified these to include a thin-wall square tube extending a few inches below and many inches above the deflector; the extension below keeps it up off of the pivoting head so it doesn't get in the way when you're loading a rocket and the extension above keeps the deflector stable so it doesn't wobble and nick up the rail. I'll get a picture of those set ups when I can.
Ask around at local farms and you may be able to pick some up for free. Concave side down has worked for us.
14th December 2016, 03:42 AM
Actually just picked one up from the in-laws' barn over Thanksgiving. I need to pop out the rivets & clean it up; thinking about blasting it then black hi-temp enamel so it's easier to clean.
14th December 2016, 01:26 PM
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