Frequently Asked Questions

1. Why should I do business with Shamrock Marketing Inc.?
   We guarantee that every customer will receive our "square deal" approach to business - quality products, delivered through unrivaled service, all for a fair price. A square deal is our daily commitment to all of you. Plus, as a small family business we’ll provide you with a rare personal touch and a little fun in your day to day business dealings.
2. What is the "Wizard" wicking disc and how does it work with my valve set-up?
   The "Wizard" is a 4" plastic wicking disc that fits on the base of the brass valve assembly in your envelope. The wicking disc has large air channels that provide additional wicking capability to the valve / coupler assembly resulting in a more efficient vacuum and proper pressure.
3. Can I eliminate cloth wicking from my retread process if I use the "Wizard" wicking disc valve set-up?
   Yes, the Wizard valve set-up gives you the option of eliminating cloth wicking from your retread process. The Wizard has undergone extensive testing across a wide range of tread designs and it outperformed traditional cloth wicking in vacuum efficiency in every application. An unexpected benefit of the Wizard is that it provides an even pressure force over the tread face helping with cushion flow and eliminating any tread peaking tendencies that may occur under traditional valve set-ups. There are some instances where the Wizard without cloth wicking may not be ideal. Contact us for further information.
4. Will I still get a proper vacuum if I use cloth wicking in addition to my "Wizard" wicking disc valve set-up?
   Yes, the Wizard is extremely flexible in application; it can be used with OR without a traditional wick device.
5. How quickly will my product be shipped once I place my order?
   Our commitment is to ship all orders with destination in the U.S. or Canada placed by 4:30 pm E.S.T. "same day". International orders may also be shipped "same day" depending on total quantities required and product availability.
6. Will Shamrock prepay the freight on my order?
   Yes, our rule of thumb is that the purchase of 16 envelopes will be shipped prepaid freight within the continental United States. For orders to Canada the rule of thumb is 30 envelopes for prepaid freight. For international orders we will typically pay freight to the port of exit. These are general guidelines and may vary by specific destination. We will always work with you to ensure your freight is prepaid or minimized.
7. Why is it that occasionally my shipment by FedEx or UPS doesn’t all arrive at the same time?
   FedEx & UPS work to deliver all packages at the same time but occasionally boxes get separated at a sorting terminal resulting in delivery at different times or days. If you believe this has happened with your order you are welcome to contact us for tracking or use the online tracking tool on our website. Click here.
8. Does Shamrock have a quality control program for the products it sells?
   Random samples are conducted on many of the products to to ensure compliance with product specifications, manufacturing quality guidelines and/or ISO regulations. Further, all envelopes and sealing rings are hand inspected during our end manufacturing and assembly prior to shipping. In addition to our inspection processes we also run ongoing field tests to help ensure consistent product performance across manufacturing runs.
9. What happens if I do have a product problem?
   All our products have a warranty against premature failure due to material and workmanship in the form of an adjustment. Our quality control helps ensure minimal adjustments. But should an adjustment arise we approach it as an opportunity to work together with our customer to problem solve, identify the cause and take steps for corrective actions in order to prevent the problem in the future. Contact us to learn more about our hassle free adjustment procedure.
10. Does Shamrock Marketing accept credit cards as a mode of payment?
    No, we don’t currently take credit cards. Orders can be prepaid or credit may be established by filling out our credit application. Click here to get a copy of our credit application. 
11. What do the number descriptions mean on your envelope sizes?
    Our envelope size description is made up of 3 parts:
    1. The Outside Diameter (O.D.) or tire height in inches.
    2. The Inside Diameter (I.D.) or center hole diameter in inches.
    3. The "Bead to Bead" (B.B.) or sealing point to sealing point in inches. (measured from side A sealing point, up the sidewall, over top of the tread and down the other sidewall to sealing point B).
    Sizes read O.D. x I.D. x B.B.
    For example; a 42x15x34 means the envelope has a 42" Outside Diameter, 15" Inside Diameter and 34" Bead to Bead. Typically we drop the I.D. when talking about sizes and reference an envelope as a 42x34 (O.D. x B.B) only.
12. How do the color coding stripes on Shamrock’s envelopes work?
    Our color coding system is based on the O.D. (outside diameter) of the envelope. The color stripe gives you a quick & easy way to differentiate your envelopes and identify the proper size for the particular tire you are retreading. The colors for your most common tire sizes are:
    
    • 295/75R22.5 = BLUE stripe
    • 11R22.5 = RED stripe
    • 11R24.5 = WHITE stripe
    • 285/75R24.5 = BLUE stripe
    • 225/70R19.5 = YELLOW stripe
    • 19.5 type tires = PURPLE stripe
13. What size envelope does Shamrock recommend I use on my low-profile tires?
    We recommend our 41" (Blue stripe) envelopes that are specifically designed for modern 75 aspect ratio tires. In the Bulldog & Top Cat brands the size is 41x13x34 and in the Evolution the size is 41x13x35. For accurate size recommendations please use our user-friendly online "Envelope Fitment Assistant". Click here.
14. What size envelope does Shamrock recommend I use on my 11R22.5 tires?
    The 42x15x34 (Red stripe) is the perfect fit for an 11R22.5 tire. For accurate size recommendations please use our user-friendly online "Envelope Fitment Assistant". Click here.
15. Why can’t I use the same envelope on both my low profile 22.5" tires, like a 295/75R22.5 and my 11R22.5 tires?
    You can use the same envelope for both tire sizes. In fact our 41x13x34 (Blue stripe) will easily accommodate both sizes and will also accommodate a 285/75R24.5 tire. We recommend running the 41x13x34 on the 295/75R22.5 for the first half dozen cures to allow the envelope to take its "post cure set" on the smaller size. After that the 41x13x34 can be used between these 2 or 3 sizes without worry. Whenever possible it is best to use the proper size envelope for the recommended tire size in order to maximize envelope life. Generally speaking, stretching envelopes onto too large a tire size and then returning the envelope to a smaller tire size will result in less than optimum life for the envelope. Learn more, click here
16. What if I have an unusual tire size to retread and I’m not sure what size envelope to use?
    Please contact your Shamrock sales representative at 800-354-4495. We would be happy to recommend an envelope size to you. Alternatively, you can try our user-friendly "Envelope Fitment Assistant". Click here.
17. Do you offer short skirt envelopes?
    Yes, we offer envelopes for all retread system applications.
18. Do you offer inside envelopes?
    Yes, we have inside envelopes for both Medium Commercial Truck tire sizes as well as OTR or Earth Mover tires. Python Inside Envelope, OTR Products.