Questions for Larry

April 1, 2009 | By Larry Lyles

Readers Ask This Restoration Pro About Soda Blasting, Paints, Remote-Control Doors, Fiberglass and More.

Where Did You Get That MP3 Plug?

You added an MP3 (Windows Media Player) plug to the side of the console in Project ’46. Where did you find such a plug? (Editor’s note: It’s seen on page 11 of the January issue.)

Stephen Sizemore Prescott, Wisconsin

You’ll have to forgive me for not being on the cutting edge where music gadgets are concerned. I still own an original “under the dash” eight-track player. I purchased a Dual brand AM/FM/CD/MP3/ WMA receiver for Project ’46 and the MP3 plug came as part of the package. My son seemed to think the plug was important so I attached it to the side of the console for easy access.

Several Comments on Soda Blasting

After reading your October article on soda blasting, there are a few points I would like to make on the subject. The Armex soda is not what I would consider “edible.” It is loaded with flow additives that help the soda pass through blast equipment that lack proper moisture control.

As for removing the residue after blasting, I wouldrecommend using a product called Hold Tight 102 ( Simply washing the project is not enough to remove all of the residue.

Stacy Stone

Chesapeake Soda Clean, Inc. Annapolis, Maryland

Stacy has been in the soda blasting business for many years now and I would consider him to be one of the top experts in the industry. Stacy has blasted parts for me in the past and I wouldn’t hesitate to use his services again.

Stacy also has an informative page on his Web site ( titled “After Soda Blasting” that really helps in this area.

My experience with soda blasting is that for the equipment to work correctly the compressor must maintain a constant 80 psi. I’ve burned out a number of 5 hp 230- volt compressor motors because of this.

Also, humidity greatly affects the process. I added three dehumidifiers to my air lines to keep moisture out of the soda blasting unit. Nor does soda do a good job on tough finishes such as Imron.

Finally, you mentioned “warping.” Warping is caused by operator error, not the blasting process.

Mike Ramey El Paso, Texas

Thanks for the input, Mike.

Is soda blasting appropriate for removing heavy rust? My ’68 Caddy convertible has some rust on the under carriage and soda blasting might be something I could do without removing the frame.

Also, can soda blasting serve as a replacement medium for sand blasting?

Tom Barnett St. Louis, Missouri

I’ve actually tried Eastwood’s Rust Removal Profile XL #50494 soda blasting media and it did a very good job removing the rust from the hood on the ’37 Ford I blasted for the article. The rust was severe enough that once I finished cleaning I found a few very small rust holes in the metal that required attention.

If you are asking about making the swap from sand to soda when using a small portable sand blast machine, the answer is that you will have to convert the machine before soda can be used. Eastwood has a converter, unit #51360.

If you are asking whether soda is the next thing and sand is on the way out, I’d say yes. I can’t even buy sand blasting sand anymore. Now I have to go with a designated blasting media, whether that be soda, plastic, glass, pecan shells or coal slag.

How Do You Enter That Car?

Where are the outside door handles on Project ’46?

Asked by several readers

There aren’t any. When I made the decision to switch the doors to “suicide” opening, that placed the outside door handles at what is now the hinged end of the doors. I could have drilled new mounting holes toward the front of the doors, but instead I elected to eliminate the outside handles altogether. This improved upon the looks of the car, but it also pushed the budget up a little.

In order to eliminate the outside handles, I had to install remote controlled latch actuators that would let me open either door with the push of a remote control button.

That’s a shot of the actuator installation on this page. This unit mounts to a bracket I welded in place inside the door and uses a shop-fabricated steel linkage rod to attach the unit to the latch. Press the remote and the actuator triggers the latch.

Remote control door latch actuators are available from a variety of street rod parts vendors and come with everything needed to make the installation.

I suggest purchasing a kit with actuators of at least 70 lbs. of pull. Some doors are more difficult to open than others and overkill in this area will keep you from pulling your hair out when the doors won’t open.

Repairing a Urethane Bumper

I have a 1978 Z28 Camaro with urethane bumpers and the front bumper has some damage that I need to repair. I’ve stripped off all of the old paint and I’m wondering what product I should use to repair this material?

Dave Jenkins Bayville, New Jersey

First you need to determine if the bumper is made of TPO (Thermoplastic Olefin), a semi-rigid plastic some automotive manufacturers used to make their bumpers. I don’t think the ’78 Camaro used TPO but I can’t be sure.

To test the bumper, sand a small area with 80 grit. If the surface comes off in chunks, go to the next test. Grind a small area with a high-speed grinder. If the surface melts, you have TPO.

If, when you initially sanded the small area, the surface sanded into powder, you have Thermo-Set plastic.

If the bumper is made of TPO, use 3M #05907 Adhesion Promoter to clean and prep the surface then make the repairs using 3M #08239 TPO Plastic Parts Repair.

If the bumper is not made of TPO, use 3M #08237 Semi-Rigid Plastic Parts Repair.

Be sure to tell your supplier if you are working with TPO as the surface MUST be prepped for painting much differently than if the bumper is made of Thermoset plastic. (Primers don’t have a problem sticking to properly sanded Thermoset plastic.) Your supplier will carry the appropriate adhesion promoters and cleaners to get whatever brand of primers and paint they sell to stick to the TPO.

Questions on Water-Borne Paints

In the November issue you had a very good article on water-borne paints. You mention using the DeVilbiss FLG 647 WB spray gun and stated that this gun was designed specifically for use with waterborne colors.

We were using HVLP spray guns 15 years ago that were made for spraying water-borne colors. Is there any difference?

I’d also like to know about using a turbine with this spray gun.

Since a turbine produces cleaner, warmer and drier air, doesn’t that make it the optimum setup for spraying waterborne colors?

Finally, if using the turbine, would it still be necessary to circulate air over the finish?

Steve Meissler Boyne City, Michigan

The first question I had for DeVilbiss when they told me the 647 WB had been designed for use with water-borne colors was “What’s different?” It turns out the seals have been improved, more parts are made from stainless, and the internal jets have been modified to better atomize water-borne paints.

As for turbine use, I can’t say one way or another. I’ve had a couple of turbine manufacturers approach me to hawk their product, but when I told them I won’t recommend anything I haven’t put through its paces they backed out.

If a turbine produces warm air, that still isn’t going to be enough to dry the water-borne paints once they are on the panel. It takes moving air to dry waterborne paints. You can use a fan or opt for the air gun system I used in the article.

In your November article on waterborne paints you failed to mention anything about how to get rid of the water after cleanup. Is this product environmentally friendly?

Maxwell Spooner Ridge, Canada

Yes, it is. Auto-Air Colors tells me their products are completely non-toxic and that you should use their Auto-Air Cleaner #4007 or Restorer #4008 to clean the internals of your painting equipment. Cleanup of the exterior of the gun and the mixing cups can be done with the water hose outside or in a sink in your shop. I don’t recommend using the wife’s kitchen sink. This paint may be environmentally safe, but it isn’t “woman of the house” safe.

(Auto-Air Colors is located in East Granby, Connecticut. Visit or call for more information on their products.)

Sealing Surface Rust

I’ve sanded, scraped and cleaned the underside of my Cuda but still have a small amount of surface rust in a few places that the sanding and cleaning couldn’t remove.

I’m going to use PPG paint products with the first coat being a coat of DPLF epoxy sealer. Is this a good product to apply over the surface rust?

Bill Lang Via e-mail

Yes, it is. Provided the surface rust is minor, the DPLF will act as a moisture barrier and completely seal off the rust, preventing it from spreading.

Compound Splatter Etched My Paint

I just finished painting my Road Runner and it really looks great thanks to your advice in Project Charger. My problem is that I applied a finishing glaze to the car and allowed the splatter from the glaze to stay on the paint overnight. The finish now seems to have been etched by the splatter. Any suggestions?

Wallace Wheeler Dallas, Texas

You’re right about the etching. Leaving compound or finishing glaze splatters on a fresh paint job will, indeed, cause etching spots. To remove the spots you will need to apply more compound. Once the spots have been removed, wash the car thoroughly to remove the compound splatter.

(Editor’s note: The “Project Charger” series followed the step-by-step restoration of Larry’s 1970 Dodge Charger and it’s now available in book form for $24.95. To order, call .)

Fiberglass Resin Recommendations

When making the fiberglass panels for the dash article in the December issue, you didn’t mention what type of fiberglass resin you used.

Did you use epoxy resin to bond the panels to the metal conduit or is there now some other type of resin that can be used to bond metal to fiberglass?

William Lane Groveland, California

Whether laying up fiberglass panels from scratch like I did in the article, or when bonding two fiberglass panels together, or when bonding fiberglass to metal, my preference is to use polyester fiberglass resin. I’ll only switch to the more expensive epoxy-based resin when I need fiberglass panels that are extremely rigid and strong. I haven’t repaired any boats in a long time, but should one come into the shop I would use epoxy resin to make the repairs then switch to polyester-based resins to do the finish work. I do, on occasion, use 3M 8115 Panel Bonding Adhesive, which is epoxy based, to bond fiberglass panels together as well as to bond fiberglass panels to metal panels.