'Should I jump in?' Joe Biden jokes he'd like to play in the sand while watching future plumbers learn how to install pipes in the ground as he makes surprise trip to Maryland union training facility

President Joe Biden made a surprise visit Wednesday to a union training facility - for the Plumbers & Gasfitters Local 5 in Lanham, Maryland - after keeping a light schedule all day in advance of his August vacation. 

'Should I jump in?' the president joked as he walked into a 'sand room,' literally a room filled with sand that trainees use to learn how to install pipe in the ground. 

Biden assured the future plumbers and the trainers that 'a lot of jobs are coming' before watching the demonstration. 

President Joe Biden made a surprise trip Wednesday to Plumbers & Gasfitters Local 5 Training Facility in Lanham, Maryland. 'Should I jump in?' he said when entering a 'sand room' plumbing trainees use to learn how to install pipes in the ground

President Joe Biden observes trainees at Plumbers & Gasfitters Local 5 Training Facility in Lanham, Maryland during a visit Wednesday. Biden was originally not supposed to have any public events

President Joe Biden watches students how to assemble correct plumbing in sinks at the Plumbers & Gasfitters Local 5 Training Facility in Lanham, Maryland. Biden is expected to head to Rehoboth Beach, Delaware over the next few days for an August vacation 

President Joe Biden takes a look at sinks used to train future plumbers during a stop at a union training facility on Wednesday. Biden told the students and teachers, 'a lot of jobs are coming,' as the bipartisan infrastructure package crawls through Congress 

'Union Strong' signs were on display all over the facility that President Joe Biden toured in Lanham, Maryland on Wednesday 

President Joe Biden mostly talked out of earshot from watching reporters as he toured the Plumbers & Gasfitters Local 5 Training Facility in Lanham, Maryland on Wednesday 

At another stop, Biden talked to students - out of earshot from watching reporters - as trainees kneeled underneath a wall of sinks. 

Signs like 'Union Strong' and 'Creating Jobs for America's Future' decorated the room. 

Biden visited a welding station and a final assembly station as well, the White House said. 

Trainees from the Maryland facility - which was about a 30-minute motorcade drive from the White House - have worked on projects including water service at the Pentagon, gas upgrades at the State Department and mechnical service upgrades on the D.C. Metro subway system.  

The White House had originally said Biden wouldn't be holding any public events Wednesday. 

On his schedule, the president, alongside Vice President Kamala Harris, was receiving the President's Daily Brief. 

He then had a closed door meeting with his top science adviser, Dr. Eric Lander, to discuss preparing for future pandemics. 

On Capitol Hill, Biden's $1 trillion bipartisan infrastructure bill is inching through the Senate, with more amendment votes planned through Wednesday afternoon. 

Asked Tuesday if Biden might delay his Delaware travels if the Senate stays in session extra days, press secretary Jen Psaki said 'the president's travel has not changed.' 

'But as you have seen the president do over the last several weeks and months, he is ready and - ready to be called into action, whether it's a phone call or bringing people to the White House or to meet in the Oval Office, and that remains the case as we work to get this infrastructure bill across the finish line,' she said. 

Biden is expected to leave for Rehoboth Beach, Delaware in the next few days, as presidents typically go on vacations - albeit working ones - in August. 

Former President Donald Trump would spend summertime vacations at his Bedminster resort, while reserving Mar-a-Lago - nicknamed the 'winter White House' - for colder breaks.

Former President Barack Obama would make summer trips to Martha's Vineyard - and then do his home state of Hawaii for Christmas.   

Earlier at Wednesday's White House press briefing, Psaki told DailyMail.com Biden would not be holding a press conference before his departure.