CASE STUDY: LEAD ABATEMENT
How Heritage Park Saved Big on Lead Abatement While Restoring an Antique Railcar
Back in 2011, staff from Heritage Park discovered an old Canadian Pacific rail car in a Calgary rail yard, filled with garbage and spattered with pigeon poop, and bought if for one dollar. They had big, revenue-generating plans for the car, but first they would need to restore it to its original glory.
The car had already been renovated three times. It was originally commissioned in 1929 as a solarium. Ten years later, it was converted into a sleeping car. It became a business car in 1964, then a work car in 1974. With each renovation, workers had simply painted over the previous coat, resulting in an overly-slick and glossy finish that couldn’t hide those telltale clusters of bubbles indicating underlying corrosion.
As with all the exhibits at Heritage Park, authenticity was the standard. To transport visitors back to the golden age of luxury travel, they needed one fresh coat of paint on a virgin surface. They also wanted it to last, so it was imperative to remove all old coatings, corrosion and debris down to a squeaky clean metal surface for an optimal bond between coating and substrate.
Before the 1960s, most paints contained lead - especially those specified for metal service - due to lead’s corrosion-inhibiting properties. The medical community had yet to draw the connection between the inhalation of lead dust and the severe and irreversible damage it causes to various human organs and systems: kidneys, reproductive, hematological (anemia), cardiovascular and the central nervous system - in particular, the brain. For thirty years after the link had been discovered, lead was still used in anti-corrosive paints because it was so cost-effective. So it was no surprise that the rail car was covered with four coats of lead paint.
The challenge for Heritage Park was to strip the rail car down to bare metal and decontaminate the surface, without damaging the substrate or putting the workers’ health at risk, and dispose of the hazardous material in a cost-effective way.
The most common lead abatement techniques are sanding and grinding, with positive and negative air pressure and HEPA filters to collect airborne dust. While this approach might make sense for restoring a hand rail, it’s prohibitively labor-intensive and time-consuming for a rail car.
Sandblasting was considered. Keeping the dust away from park visitors wasn’t an issue: surface preparation was occuring in January, so Heritage Park had built a separate enclosure in their wood shop. But no amount of containment could alleviate the health risks of working in the eye of a storm of sand and lead dust.
Heritage Park evaluated blasting with dry ice, which produced much less dust, and minimized heat from friction that could warp an antique metal surface, but dry ice was too soft to impart the necessary anchor pattern on the steel surface for optimal coating adhesion.
Wet abrasive blasting fit the bill perfectly, combining the high production rates of sandblasting, but suppressed the airborne dust up to 95%, while keeping the metal substrate cool and warp-free.
First, tarps were laid around the rail car and a low berm was constructed to hoard the water, debris and spent abrasive.
Then we rolled on Lead Out paint stripper - a biodegradable, soy-based product that caused the lead to bubble to the surface, become inert, and slough off. After three passes, we bagged the waste and disposed of it in a regular landfill, saving on hazardous material disposal costs.
Finally, we wet blasted the exterior and interior of the car with a fine-grained garnet abrasive.
During the process, we uncovered some original gold leaf stencilling from the rail car’s initial duty as a solarium. Because our Geoblaster equipment allows for adjustable blast pressure down to 30 psi, we were able to remove just the three most recent paint coats to reveal this original artwork that Heritage Park staff copied, and later recreated during the final restoration.
Surface preparation of the exterior and interior was completed in 3 weeks, followed by painting, and the rail car re-entered service in June 2015. Today, you can enjoy a two-hour fine dining experience as an antique steam engine pulls the River Forth Dining Car around Heritage Park.
If you're in the market for lead abatement in Alberta, put Geoblast - the wet abrasive blasting experts - on your short list. Give us a call at (780) 612 8860, drop us an email, or fill out this form.