Dust collector vented outside. How do I trim/seal the vent hood on the outside of the shop?

[MarkE]

After spending another 3 hour session cleaning the filter on my Oneida DC, I decided to bite the bullet and eliminate the filter by venting outside.

Got the whole thing done, except, I don't know the correct/best way to finish and/or seal where the vent hood mounts to the outside wall.
The 8" hole is cut through the inside and outside osb and the vinyl siding has been trimmed to fit the hood mounting flange.

With the hood in place.

The main concern here is to prevent as much water as possible from getting under the siding.

So what would you do to finish this off?

 

[Gotcha6]

Step flashing and a premium grade of caulk - not silicone, but PL400 or a polyurethane that has some elasticity to it and won't harden and crack.

 

[Charlie]

I would use J-Channel as used around windows, etc. Then caulk between J-Channel and vent.

 

[SteveHall]

Full perimeter flashing, up under the siding is 90% of the solution.

Think of sealants as the second level of defense. Stick with 100% silicone for exterior use, it's generally the best performing sealant. Polyurethanes are cheaper but don't have as much long term expansion-contraction flexibility or bonding adhesion. Avoid latex. There is variation across products, so product-specific testing is revealing. CSI is a good impartial resource of building product info. Here are a few relevant articles: Durability of Elastomeric Sealants and Sealant Joint Solutions.

 

[Skymaster]

J channel then silicone

 

[MarkE]

Thanks for all the responses.

I went with the J-Channel but did not use any flashing. I added a couple of staples to to make sure the house wrap was secure around the hole. Also put a couple of beads of silicone caulk around the hole and about 1/2" from the outside edge of the hood flange, then screwed the flange to the osb sheathing. Took off a couple of courses of the vinyl siding and installed the J-Channel around the hood and re-installed the siding.

The last step will be to caulk between the J-Channel and the hood. I ordered this caulk for that job. it should get here by Monday.

The view from inside.

 

[Charlie]

Looks good. You are going to enjoy not having to mess with filters. I've been blowing directly outside for about 28 years and wouldn't have it any other way.

 

[JimD]

Looks like I am too late with this suggestion but I like Duo Sil made by Siloflex. It is a urethane. I use it both outside and inside when I need to be able to paint it. The installer that put in our new windows used it on the aluminum he bent up and used around the new windows. In that application it attracts dirt more than the aluminum. But it weathers well (i.e. retains flexibilty and stays stuck in place). Inside it shrinks less than latex or silicone and sticks very well. I've had to remove trim that was caulked with it and it was challenging. You can cut it with a utility knife but with difficulty and if you try pulling it off, you will damage the wood. After 5 years. I get it either locally or from Amazon.

 

[nn4jw]

Looks like I am too late with this suggestion but I like Duo Sil made by Siloflex. It is a urethane. I use it both outside and inside when I need to be able to paint it. The installer that put in our new windows used it on the aluminum he bent up and used around the new windows. In that application it attracts dirt more than the aluminum. But it weathers well (i.e. retains flexibilty and stays stuck in place). Inside it shrinks less than latex or silicone and sticks very well. I've had to remove trim that was caulked with it and it was challenging. You can cut it with a utility knife but with difficulty and if you try pulling it off, you will damage the wood. After 5 years. I get it either locally or from Amazon.

Duo Sil is what was just used around our new windows too. I haven't found anyone in my area that sells it retail though.

 

[MarkE]

Duo Sil is what was just used around our new windows too. I haven't found anyone in my area that sells it retail though.

Looks like Amazon carries it.
https://smile.amazon.com/Siroflex-D...pID=31GCxY6x8eL&preST=_SY300_QL70_&dpSrc=srch

 

[nn4jw]

Looks like Amazon carries it.
https://smile.amazon.com/Siroflex-D...pID=31GCxY6x8eL&preST=_SY300_QL70_&dpSrc=srch

Thanks, Mark. When I looked a few months ago they didn't have it in any affordable quantities.

 

[JimD]

You can email cservice@siroflexinc.com or call 1 800 359 6398 to find a local distributor of Duo Flex. Their plant is in Greenville, SC.