Trouble twisting Duravent Pellent Vent Pro together

I finally got down to business and assembled the vent for my new stove but had a lot of trouble twisting the Pellet VentPro together. There are a couple of pieces where I could only get the tabs to grab just a little, even with two sets of hands on them.. Any suggestions/tips for getting these to twist together?

The o-rings all had a little silicon on them. The instruction book says the lubricant is available throught Duravent, but I don't want to wait. Is the silicon anything special?

Thanks

Is this 3" or 4"?

3" and oil filter wrenches work very nice.

Use anti seize and strap wrenches.

I'd be concerned that the strap wrenches would collapse the pipe, but if it works, it works.

rubber strap wrenches