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Sealant Gun: SEMCO vs KNOCKOFF ?

Master Designs

Well Known Member
Has anyone purchased the generic (knock-off) sealant guns sold by ACS, Yardstore, etc? They are about $110 to $130 new, whereas a used Semco 250 gun on eBay fetches about $60 to $80 with unknown condition. Is it better to go new, or go used to get the quality of a Semco?

P.S. I don't want to apply sealant with popsicle sticks or large plastic syringe. :D

ACS Gun #16573 (NEW): https://www.aircraftspruce.com/catalog/topages/sealantgun3.php

eBay Semco #250 (USED):
https://www.ebay.com/itm/Semco-250-with-2-5-oz-and-6-oz-tube-Pneumatic-Sealant-applicator-aviation/113740599201
 
Love my Semco. I bought used on ebay for about the same price you're seeing but would pay full retail if I had to build another fuel tank. I also use it with a long nozzle and RTV for the baffles.
 
bought a cheap one off eBay. Great control of the flow rate. I really liked building the fuel tanks and probably because I used the semco gun.

Of course, i say that before putting in fuel. Passed the ballon test, who knows about in action.
 
Semco, Used, from Brown Tools

I got a used Semco gun from Brown Tools after trying all the other methods. I absolutely love it! Better than the caulking by hand as there are no hand cramps and excellent control. I used the 2 hour cure sealant and needed a little now and then. I put the excess in the freezer, got it out and used it from time to time and put it back. I could get 3-5 thaws from it and 45+ days in storage. It was getting a bit thick at the end but the Semco pushed it just fine. It even peeled out of the stock plastic container and it got reused.
 
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