​Distributor of quality Graco Parts And Services. Urethane Supply features spray rigs and equipment for foam insulation and roof coatings.

Urethane Supply, Inc.

PO Box 950 Hwy 280 West Claxton GA 30417 US
In this edition of Tech Tips, I’d like to talk about closed-top (“tight head”) drums vs. open-top drums. Recently one of the chemical manufacturers announced that they would start shipping their A side (Iso) material in closed top drums. Sprayers that have been using open-top drums in the past have simply been moving a drum lid, with the transfer pump and desiccant drier assembly / recirculation line already attached, from drum to drum. With the closed-top drums, that is no longer an option. However, we have a few items available that may make changing drums a little easier.  

​For the desiccant drier assembly we have a fitting that will screw into the ¾” drum opening and thread onto the bottom of the desiccant drier assembly. This will make it unnecessary to detach the recirculation hoses from the desiccant drier assembly. If you are not using a desiccant drier (which you definitely should be), but rather have your recirculation hoses attached directly to the ¾” drum opening, there is a quick connect available to simplify this connection. These quick connects work just like air quick connects, however they are specifically made for fluid applications. With the fluid type quick connects, both the male and female halves seal off when they are disconnected. These fluid quick connects can also be used even if you are using a desiccant drier assembly, but in most applications will be unnecessary. 

​If you are using diaphragm pumps, that utilize a riser or “pick-up” tube, you will simply un-screw the star shaped bung adaptor from the 2” hole and move the riser to the next drum. The bung adaptor should swivel on the tube, making this an easy transition. If yours will not swivel, the riser tube can be dis-assembled and cleaned with gun solvent or the riser tube assembly can be replaced. In either case the bung adaptor should be kept clean. It is also helpful to lightly lubricate the threads of the bung adaptor to prevent seizing.  

​Most 2:1 “stick” pumps also use a bung adaptor that is separate from the pump itself. In these cases, simply raise the pump slightly and unscrew the bung adaptor, then move the pump with bung adaptor to the new drum. Re-thread the bung adaptor into the new drum and lower the pump and re-clamp the bung adaptor. Once again, it may be necessary to clean or replace the bung adaptor and always lubricate the threads of the bung adaptor to prevent seizing. 

​There are a few stick pumps out there that do not use a bung adaptor. With these pumps you will literally have to thread the pump itself into the 2” drum opening. If you have this type of pump, you will want to use a fluid quick connect set-up, which we have available, so that you won’t have to unscrew the hose from the pump each time you change drums. Again, these work just like an air quick connect, except that both the male and female sides seal off. The only trick to these quick connects is to keep them clean and lubricated to avoid seizing.  Even if your stick pumps have bung adaptors, you may find these quick connects handy, but they are not mandatory.  

​I always recommend changing your drums when the material gets down to a level of approximately 4”, to avoid introducing air into your spray system. With open top drums, it was easy to pour this remainder over into the next drum. However, with closed top drums it’s not so simple. We have two types of funnels available to make it simple again. One type threads directly into the 2” bung opening. The second type sits on top of a drum, covering almost the entire drum top, and has a spout that goes into the 2” bung opening. The second type will remind you of an oil drain pan used when changing the oil in your car and is made of plastic. 

​Many of you have been spraying closed cell material and are already familiar with the closed top drums. The suggestions I have made can be applied to your situation as well.  We also have drum de-headers available, should you wish to cut the top out of the metal closed top drums once they are empty. 

​If you have any questions, whatsoever, regarding your specific set-up and how best to adapt to the closed top drums, please give us a call. We will be happy to help you find solutions for your specific needs.

Wyndell Gossett

Tech Support Dept.

Urethane Supply, Inc.

Phone: 601-693-8220

Closed Top Drums vs Open Top Drums