DIY 5" Blast gates

I see why 4" duct is so popular. Right or wring, it is available. There are many fittings and hoods available in 4". I'm not seeing as much available in 5" or 6" which implies, I'm going to be making my own. Not a worry if I can find parts to do it. Therein lies the rub. If I go with 5", which means metal. How do you make blast gates and dust hoods? I see some ideas for 5" dust hoods, but they all appear to have sheetmetal edges (ie., non-blunt or possible sharp edges compared to PVC or ABS). I have not found any plans for DIY 5" blast gates. What has been done for DIY 5" blast gates?

5" ducting and fixtures are readily available, jut not locally off the shelf. They are easy to find on the internet. Same with 6" as well.

5" blast gates are about $20 from various vendors, so unless you really like to DIY stuff, I'd just buy them. You can build your own collection hoods with either metal flashing (you can hem the edges so they aren't sharp), or plywood, and connect to hose or duct with a 5" HVAC starter piece.

Check out Grizzly. They sell a lot of larger duct work componants for DC. They have metal and plastic to suit your needs.
https://www.grizzly.com/search?q=5+blast+gates
Only problem is the metal gates are extremely high dollar.

I just buy 5" aluminum blast gates. They are readily available...I have a bunch of them in my shop.

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Originally Posted by Steve Eure

Check out Grizzly. They sell a lot of larger duct work componants for DC. They have metal and plastic to suit your needs.
https://www.grizzly.com/search?q=5+blast+gates
Only problem is the metal gates are extremely high dollar.

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Therein is one reason why I am looking DIY. The second it that I would like to mount the gates out of the way, when they are out of the way, I won't be able to reach them easily, thus I will be automating them.

I don't recall from shop class a way to hem a circle such that there will be no sharp edges. All the methods I can recall and have found rely on cutting finger and bending them over. That still leaves sharp edges, perhaps even sharper. (P.S. it is the hose end I am worried about being sharp).

Obviously you would have to cobble some sort of connection method. I cut short sections of pipe, you could do the same for metal sections.

Attachment 445908 , Attachment 445909 . Attachment 445910

Let me try approaching this from a different angle.

At some point the duct work, what ever size it is, must transition to flex hose to get to the machine. How do the sizes of the flex hose align to each of the possible duct sizes?

4" hose to 4" ABS: Matches well

4" hose to 4" PVC: 4" hose is smaller than 4" PVC

5" hose to 5" metal:

6" hose to 6" PVC:

6" hose to 6" metal:

Hose toi metal is easy since you can manipulate the hose over the metal including if you need to make minor adjustments to diameter of the hard pipe at the hose connection. Some hose is more flexible than other hose in this respect. You can also create a metal sleeve that slips inside of the hard duct (metal or plastic) that permits clamping on a hose. Etc.

You can make your own blast gates for metal duct in the same way you can do the same with plastic duct if you wish to do so. If you use non-metal components that electrically isolate the drop side of the duct, it's not a horrible practice to provide a wire jumper across the gate to maintain the ground. This is mostly for your own comfort.

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Originally Posted by Jim Becker

Hose to metal is easy since you can manipulate the hose over the metal including if you need to make minor adjustments to diameter of the hard pipe at the hose connection. Some hose is more flexible than other hose in this respect.

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So true, but unfortunately I've found this out after purchasing the hose on several occasions. Perhaps some suggestions from people as to particular brand hoses (or links) that easily fits over the metal fittings would be helpful.

I've done 5" fittings on a number of my machines (Felder, so metric), but typically have used 6" blast gates then transition down to the machine.

Yea, my big machine ports are all 120mm which is "similar" to 5" with the J/P off a 6" drop. I put a 6" to 6" reducer right under the 6" gate there. The slider comes off a 5" drop from a 6" main. I probably slightly altered the end of the metal drop to clamp the hose on that one, but it was a long time ago and it's buried behind the machine. One of the things like like about the metal quick connect (Nordfab type) hose adapters I'm using on a few drops is that they are "hose" size which makes the job super easy. Albeit super easy at a price.

I've been buying the PowerTec hoses off Amazon as of late and they seem pretty flexible. Sometimes a little heat can help, too.

I think I have been spoiled with the 4" hose. The hose fits on the dust hoods with ease and quick flip hose clamps. On the other end is a quick connect fitting for connection to the quick connect blast gate. This has worked well so far, and I was thinking something similar would work well going forward. I have a small shop, 4-5 drops for 8 machines with dust ports. So easily moving machines and hoses is a must.

Yea, quick connections make for easy flexibility when you need to frequently change things around. The good ones are air tight, too. The magnetic type that recently came on the market are quite interesting and actually offer the potential for DIY given the easy availability of strong magnets.