I have been prevaricating for months about how to progress to the bare metal stage of the renovation, by that I mean how the hell am I going to get all the paint and underseal off. There are many options, some liked more than others. I have considered the most common ones based upon ease, efficiency, cost and timescales:
Most cost effective, I think, not sure about that though once you have taken into account all of the materials used, However the thought of spending days days covered in dust and chemical strippers doesn’t really appeal to me, plus all of those nooks and crannies and my neighbours. I have heard of the difficulty in getting rid of undersell using heat guns as well. This may seem as a bit defeatist to some of you reading but, I am just laying down my pros and cons. Cost- a lot of man hours and new lungs, plus multiple flap and wire brushes for the angle grinder or paint stripper.
A science all of its own. I looked firstly at buying an air compressor and the necessary kit to carry out this myself, The advantages in my little mind were if you are going to pa £1000 for someone else to blast the car, then why not buy the kit yourself and have it and carry out other work using the blast set up once purchased. I had visions of a tent setup in front of the garage and carrying out the blast in an enclosed environment. However it seems that unless a really heavy duty industrial compressor is used (at a high cost) then little practical blasting can be done. I also didn’t like the idea of removing more metal than was necessary with the blast. I looked at mixed media abrasives, which seem a promising prospect and are more kind to the cars metal. Also a huge growth in Soda blasting has happened over the last couple of years with a number of companies in the UK offering this. The advantages are that the soda crystals (not your baking soda at home) when they impact on the paint, explode and release energy that strips of the paint leaving the underlying metal pretty much untouched. Good for paint and but bad for rust as it won’t remove it, so a follow on more abrasive media is required,. The soda crystals also won’t attack rubber of chrome or the like. So a follow on more abrasive blast wit the likes of Aluminium Oxide is required. Ballpark costs £800-1000 without transport. Makes sense to also apply an etch primer straight after the blast.
Concerns are that you have to wash the car down to really remove all of the soda, and in doing so you may end up with it hidden in the seams and leaching out later on (My personal view). I think some of the other media that can be used to blast may be more effective and kind to the car body, such as plastics, but would really need to test that out across a range of metals and using a heavy duty blaster which I don’t have.
There are a couple of well known companies carrying this out, SPL being the biggest possibly. Sounds good on paper, my own personal concerns were once again leeching out of chemicals later, and also transport costs up and down to their works. Excellent rust protection having the galvanising, but cost For the full blown dip strip and galvanising process probably close to £3000
4. Thermal or Pyrolitic:
Place the whole car body in an oven and the bake off the coatings. I researched different companies and found one fairly local, Beadshot in Halifax. They will pack the car shell and panels into a large oven of and using a ramped program ash off all coatings. The staged program removes volatiles first with extraction, and then steps up to 400 Deg C , then cycledown. All to ensure full removal and nowarping of panels. After the bake the shell and panels are blasted using fine aluminium oxide to remove any rust and to key the surface. Finally a etch prime is sprayed to stop any flash rust during storage or transportation. The beauty of this whole process to my mind is that you remove all coatings including undercoats, and dont blast the shell and panels too severely. Cost about £1000 in total excluding transport cost.
I decided upon Thermal processing and booked the body into Beadshot in Halifax for 18th of June 2012. The process will take about a week and a half. Pictures to follow on a separate post.