Duct strapping for rack build?

[kmosmen]

In the process of building 1.4 and 1.3 racks..... Been reading a lot here and this is a great community. Thanks Dave!

So why is it that no one has used 3/4" duct strapping to secure the circumference of a rack from a bad lift charge? This product in particular:

http://m.homedepot.com/p/Basset-Products-3-4-in-x-50-ft-Perforated-Duct-Strap-DS50-1-22B/205871087

A blown tube would keep the remaining aspects of the rack intact.

Thoughts? Comments?

[ras1986]

The point of a rack is not to keep the shells from blowing tunes apart. It's to stabilize the mortars and other reasons like convenience. Anyway there isn't much that will keep everything from blowing apart. This stuff is designed to fail safely. If you add strapping especially metal it will just shear and turn into shrapnel.

[kmosmen]

I understand the purpose of the rack. But stuff happens and bad lift charges can cause tubes to blow. When that happens, do you want the rest of your rack trashed or do want the remaining tubes to be usable?!

Shrapnel from duct strapping??? No way....in fact, it will most likely limit wood shrapnel if it's attached to the wood at the location of each mortar tube.

[ras1986]

I wanna see what would happen with a 3 inch salute upside down in a rack with and without out strapping. I guarantee the outcome would be the same. Think about this.. a 3 inch salute has probably the same or a little less power than a stick of dynamite.... do you think a thin piece of cheap steel stands a chance?

[PyroJoeNEPA]

Are we trying to re-invent the wheel here? If there was any merit to its use, you would see the metal strapping being used. Not happening. The safety factor is the concern. You will see videos on You Tube of companies in Mexico & Europe that have their racks strapped together with high strength banding steel like you see around very large & heavy cartons. [Much stronger than the product you referenced.] You don't see it here in the USA for a reason. Lots of things are done in the pyro world that are not "acceptable" here in the USA. Safety Safety Safety.


a 3 inch salute has probably the same or a little less power than a stick of dynamite. ras...I see the comparison you are trying to make, but there is a great difference between the type and force of a stick of dynamite and a salute. A flash powder burst will destroy whatever it is sitting on--whereas dynamite is intended to be confined to transfer its energy. I saw someone several years ago put a half of a stick of dynamite on a picnic table & light it--no damage to the table--all the energy was dissipated up & around the flat surface. A salute would have made splinters of the table.

Back to the OP's statements--if you are dealing with 1.3g products & have a tube blow out, you most certainly would have pieces of metal flying around if the strapping was used.
The reason many people use OSB for their lower side boards on their racks is that it will not splinter like plywood would. Top rails would not get the brunt of the explosion, so it is commonly used for top rails.

[ras1986]

Are we trying to re-invent the wheel here? If there was any merit to its use, you would see the metal strapping being used. Not happening. The safety factor is the concern. You will see videos on You Tube of companies in Mexico & Europe that have their racks strapped together with high strength banding steel like you see around very large & heavy cartons. [Much stronger than the product you referenced.] You don't see it here in the USA for a reason. Lots of things are done in the pyro world that are not "acceptable" here in the USA. Safety Safety Safety.

ras...I see the comparison you are trying to make, but there is a great difference between the type and force of a stick of dynamite and a salute. A flash powder burst will destroy whatever it is sitting on--whereas dynamite is intended to be confined to transfer its energy. I saw someone several years ago put a half of a stick of dynamite on a picnic table & light it--no damage to the table--all the energy was dissipated up & around the flat surface. A salute would have made splinters of the table.

Back to the OP's statements--if you are dealing with 1.3g products & have a tube blow out, you most certainly would have pieces of metal flying around if the strapping was used.
The reason many people use OSB for their lower side boards on their racks is that it will not splinter like plywood would. Top rails would not get the brunt of the explosion, so it is commonly used for top rails.

Thank you for shedding light on this. You always have something smart and informative to say. Thank you!