Dec12

Rodding 101

Ben Harris

Ben Harris

Why Even Consider Rodding?

Rodding stone is an insurance policy for your business.  Just like most insurance policies, there is a specific cost that buys a guarantee against some kind of loss.

Main image courtesy of https://surfacelink.com/my-granite-cracked-in-front-of-the-sink/

Rodding Granite
Rodded Granite

 In the case of rodding granite, the majority of your ‘cost’ would be the time and labor involved in installing the rod since typically the rods themselves and the adhesives are relatively inexpensive.  The potential ‘loss’ could be a broken workpiece (which in some cases is one-of-a-kind), time and labor to fabricate a new workpiece, and most importantly your reputation.

Cost vs Potential Loss

 

Factors to Consider

To be able to make an educated decision on if you are going to implement rodding in your shop, there are many variables to consider:

  • The thickness of stone. As an example, stable 3cm granite may not require rodding reinforcement on some sink cut-outs, whereas the same shape and material in 2cm granite needs to be rodded.

  • The stability and integrity of the stone itself. Stable granite with a tight crystal structure may not require rodding, but marble or any other material prone to breakage will. Especially materials that come from the manufacturer with fiberglass reinforcement mesh will most likely need reinforcement rods in any vulnerable areas, such as in front and behind sink cutouts. Also, all natural stones have imperfections. Natural stone Manufacturers fill natural cracks and fissures with plastic resin and polish the tops. Some feel the need to place rods across these cracks even if they are in the center of the slab, to prevent cracks from expanding.

  • The application of the stone top. Example: A large cut-out, common on kitchen sinks or farm-style kitchen sinks, will require rodding because very little stone is left in front and behind the sink and these are definite weak spots. However, a smaller oval cut-out on a bathroom vanity in some stones may not be prone to breakage and therefore not require rodding. If the counter will serve as an overhang bar or you feel that there exists the possibility that excessive weight could be applied to a stress point in the granite, it could be a good idea to consider rodding the edges.

 

Does Rodding Really Work?

No Rodding
No Rodding

Fiberglass Rodding
Fiberglass Rodding

Stainless Steel Rodding
Stainless Steel Rodding

The short answer is YES, it works very well, provided it’s done properly. Click HERE to read a very informative article from Stone World Magazine. Countless experiments have been conducted by reputable institutions (including MIA) to prove that rodding is indeed effective. Click HERE to see an impressive YouTube video demonstration.


What Kind of Rodding is Best?

Not all rodding options are created equal. We recommend either stainless steel rod or a good quality fiberglass rod. In some cases, steel will be stronger than fiberglass. But for many shops, fiberglass is more convenient and sufficiently strong. A rusting non-stainless rod is very bad because it will expand and can eventually crack the stone ending up in the very thing you wanted to avoid (see the image below from TheFabricatorNetwork.com).

Cracked granite from rusty rod
A rusting rod will expand and can crack the material

If you are certain that moisture won’t be an issue, and that the rod will 100% encapsulated in the adhesive, stainless steel may not be necessary. However in our opinion it’s always better to be safe than sorry.


What Kind of Adhesive Should I Use?

Most shops use polyester resin. However, epoxies are generally stronger and adhere better than polyester adhesives. Also, while it’s always best to make sure the stone is completely dry before applying adhesive, if there is any moisture present, epoxies will most likely still adhere whereas polyester adhesives may not. Keep in mind that some epoxies take a long time to cure, so to avoid costly delays, choose one that has a cure time of less than 30 minutes. Also, if using polyester resin, mix the proper ratio of catalyst to resin and allow to cure for 10 minutes or more after adding it to the channel. If you mix it too hot (too much catalyst) for a flash cure, the resin will likely become brittle and limit the effectiveness and strength of the rodding area.

 


Recommended Procedure for Rodding:

  • After cutting the stone to size, lay out the piece for additional cutouts such as sinks, cooktops, faucets, outlets, notches and other cutouts.
  • Once you have completed the layout of any cutouts, lay out the location(s) for the rod(s). Be sure that the rod(s) will extend beyond the cutout area by at least 6 inches on each side and will not interfere with any faucet fixture holes.
  • Place the top face down on a smooth, soft, flat, level and clean surface and use a carpet pad or the like to protect the polished surface. NOTE: If the work surface is not level, a flowing epoxy will run out of the rodding channel.
  • Select the blade you plan to use. We recommend using the BQTR6 - 6" QT™ AGX Rodding Blade. Use one blade to cut 1/8" channels for fiberglass rod or stack two on the QT™ HandChange™ Hub for your 1/4” rods.
  • Mark where the blade should cut on your workpiece. The channel should be approximately 1/32” wider than your preferred rodding material and 1/64” to 1/32” deeper than the rodding material depth. Do not cut any deeper or wider into the material than required – this will negate the purpose of rodding and weaken the stone further. Set your AccuGlide Depth Gauge for desired maximum depth to avoid cutting too deep.
  • Cut the rod slot in the marked section on the bottom of the stone. Be sure to extend your cut far enough for the full length of rod to fit in (allowing for the curve of the blade).
  • Place the rod into channel to verify the fit.
  • Remove the rod with a putty knife or a flat screwdriver.
  • Thoroughly wash out the rodding channel and dry it with compressed air.
  • Abrade/Scuff the rod with a coarse grit abrasive, clean it (especially removing any oil residue), and allow it to thoroughly dry.
  • Mix an adhesive and pour or use a putty knife to fill the slot into the slot of the stone. Note: Make sure to apply adhesives in a well ventilated area.
  • Quickly insert the rod fully into the channel. Then scrape the surface flush using a steel putty knife. Make sure the rod is completely encased in adhesive. Remove any excess adhesive.
  • Allow the adhesive to cure completely before moving the stone.

Rodding Made Easy

AccuGlide offers a fast, easy and economical solution to cutting rodding channels. Use a single BQTR6 - 6" QT™ AGX Rodding Blades with a the AccuGlide Classic saw to cut 1/8” channels for fiberglass rod. Or stack two BQTR6 Rodding Blades on either the AccuGlide 3000PRO or 3000QT model saws to cut 1/4” channels for stainless steel rodding.

BQTR6 6in QT Segmented Blade
BQTR6 - 6" QT™ AGX Rodding Blade
Stacked BQTR6 6in QT Rodding Blades
Stack two BQTR6 Blades on 3000 Model Saws


Resources and Other Useful Articles