Thank you👍

@S K ,so for example 10x6 ID will the cuts be : 10 3/4x6x10x6 ?

@@sdsd4284 Correct! But again, this is only when using the Amcraft layout square (with the V-groove cutters) because the design of the square will account for the thickness of the board on the 2nd, 3rd, and 4th side cuts (and just make sure to measure these 2nd, 3rd, 4th, sides from the right most cut of the v-groove you just made previously). It's that first piece where you have to add the 3/4" to accommodate for the thickness of the board coming back around to side 1 from side 4 (because you're not cutting the left most part of that first side which remains flat, and you're cutting with the shiplap tool on the last cut which is also leaving that right most side flat as well [i.e. not v-grooved]). Hope that makes sense. The directions in the Amcraft pamphlet show it pretty clearly as well. This guy (kzfaq.info/get/bejne/a5ejZMdmxsyvloE.html) also does a good job with the exact same tools (in the comments he replies that he uses 5/8" at the first cut instead of 3/4" because it works out better for him [maybe doesn't make the board too tight when he tries to pull it together]. A male and female shiplap hand tool and an angler tool (kzfaq.info/get/bejne/n8h1m8mjua-afWg.html) will also make ductboard fabrication a lot easier too. Good luck!

@@Babysoft thank you .will be trying out this method .

Somewhat correct if you have this square first cut add 3/4 an last cut add a 1/4 done only for 1”1/2 duct board!

That depends everyone has there different methods of how to attach it properly, typically just make sure the duct is nice and flush to the unit, then very carefully put mastic on the inside, you can also make a female shiplap on the side of the duct that attaches to the air handler then put mastic inside. After you tape everything up turn blower on and check for air leakage.

If you go into my description tab below video you should be able to find all the links to the tools in video, I copied and pasted it for you. I hope these links are helpful 👍 Down below are the tools used in video👍 *Cutting Duct Board w/centerline method using amcraft tools- kzfaq.info/get/bejne/iNKaldaeyaq2Znk.html *Malco fasgroove shiplap tools for duct board-kzfaq.info/get/bejne/nrOIlaipv9rPlqs.html Amcraft Layout Square- tinnerstools.com/amcraft-collapsible-layout-square/ Amcraft Blue Tool- www.amazon.com/Amcraft-insulation-Blue-Duct-Tools/dp/B01M9GJPLI/ref=mp_s_a_1_2?dchild=1&keywords=amcraft%2Bred%2B%26%2Bblue%2Bduct%2Btools&qid=1612741536&sprefix=amcraft&sr=8-2&th=1&psc=1 Amcraft Red Tool- www.amazon.com/Amcraft-insulation-Blue-Duct-Tools/dp/B01MG5ZGDW/ref=mp_s_a_1_3?dchild=1&keywords=amcraft%2Bred%2Btool&qid=1612741697&sprefix=amcraft%2Bred&sr=8-3&th=1&psc=1 Clinch stapler- www.amazon.com/Outward-Clinch-Stapler-Manual-Heavy/dp/B002YES78C/ref=mp_s_a_1_3?dchild=1&keywords=bostitch+clinch+stapler&qid=1612741885&sr=8-3 Duct Board- www.budgetheating.com/Acoustic-soundboard-Case-4-foot-X-10-foot-sheets-p/232002.htm

Lol, I hear you bud. Here in florida it’s all fiberglass and flexible ducts for residential, commercial application is when we will usually do the metal ductwork. Try brushing some fiberglass mastic in between the joints or cuts. Hardcast/Carlisle - CCWI-181 is a versatile indoor/outdoor water based duct sealant for use on all types of metal duct, glass fiber duct board and flex duct, as well as duct fabric and flexible tubing runouts. It incorporates a built-in polyester reinforcement for exceptional strength with UV inhibitors for outdoor use.

@@AZSolutions92 I live in Florida now too (Boca, originally Michigan) I never seen fiberglass duct work till I came here. We always wrapped the metal with insulation if we need to, but doing it that way you can at least seal the metal first with mastic. It was eye opening to see fiberglass used as air supply. Anyone that has ever worked with fiberglass knows how bad it can irritate the lungs, skin, eyes. I have an older home 1978 I can appreciate the simplicity of the fiberglass duct work and its a cool system from a installers/fabricators POV but I'm amazed people want to breath this stuff. I am 100% sold on mini splits here in south Florida. As soon as this current system dies its all coming out and two 3 zone mini split systems are going in (4 ceiling cassettes and 2 concealed duct unit) with short metal ducts and spray foam attic. I have flat roof section so ceiling cassettes wont work in all parts of the house and I find the wall mounts are kind of ugly unless its a really large space. The redundancy of having 2 independent systems with multiple indoor units is a huge selling feature in itself. If one system or piece goes down you still have AC and not having AC here is a no go. On top of the efficiency health and comfort a mini will provide over a traditional split system. My current air handler is in the garage and what a mess that is. It sweats like crazy and is starting to rust the bottom out even the inside of the unit uses some cheap foil faced fiberglass insulation. I dont even want to know what my indoor air quality is (ignorance is bliss) but I know its not good... Not sure who started these building trends back in the day here in Florida but air handlers in non conditioned space, fiberglass duct work, a single air return for the whole house, supply duct work in unconditioned attic. Not only is each of these methods a bad idea its honestly the worst possible way it can be designed and Florida decided to not only adopt one method but role them all up together in one big shit sandwich. Best of luck bud I appreciated the knowledge of how the fiberglass ducts are made even though I will never be making one 🤔

If you want outside dimension 20x21 duct then u need to minus 3” off each dimension so it should be 20-3=17 and 21-3=18. The inside dimensions of the duct u need are 17x18. I hope this helps👍

Do you still add 1/2 on the first cut and - 1/4 for 2 and 3 cut?

Yes, I’ll add those to my to do list👍

Thanks for the tip, I will try that👍

Yes ill add that to the list of videos ill be making. Once i get my hands on some 2” duct and the 2” amcraft duct tools ill make a video of how to use them. Also you said that on your 4th cut u do (ID + 2-7/8” ) try this instead and see if it works for you(ID + 3-5/8”) Example: 10”x 6” duct Inside dimension 1st cut red tool: 10+2-7/8= 12-7/8” 2nd cut red tool: 6+3-5/8= 9-5/8” 3rd cut red tool: 10+3-5/8= 13-5/8” 4th cut blue tool: 6+3-5/8=9-5/8” The blue tool needs to be set-up for shiplap with skinner as well. I hope this example is helpful👍

The OD is 13x9 since the duct im working with is 1-1/2”, the OD is 3” more from inside Dimensions

Ok kool

Yes i agree, I followed instructions for using layout Square and I kept getting 1 side a little bigger than the opposite side, i then bought another layout Square and v-groove tools thinking mine were defective, but same issue so instead i used centerline method and compared it to layout Square method and found that the layout Square method does work ok but is not as accurate as the centerline method, thats why I started adding and deducting in video to match the centerline method. With a little practice the layout Square method i did in video is the fastest way to cut duct besides using a big duct cutting machine.