Modifications to my blasting rig

I have finally got myself a second compressor at a bargain price, whoooo! …although I later found that it had a cracked air manifold with a bodged repair, boooo! …thankfully it was very cheap to replace the whole damaged piece. Anyway, after lots of head scratching I linked them up to each other as shown in the photo below:

With both compressors running in tandem I can pretty much blast constantly without ever dropping below 100psi. The only thing to be considered is the duty cycle of the compressors, particularly as they heat up quick! So far I have been blasting for about 10mins and then take a break (well, finding something else to do) for 10mins to allow the compressors to cool down. It is a huge improvement, but blasting is still a slow process with a relatively humble set-up such as this!

To take care of the dust cloud issue, which fills the cabinet within 5mins of blasting, I initially attached a domestic vacuum cleaner to the outlet. However, it proved to be far too powerful for this cabinet and almost sucked the rubber gloves off of the mountings! So, after some playing I devised a rudimentary solution using an old 12V pump (the camping type, typically used to inflate air beds) connected to the inlet hole. The idea being that the pump creates higher air pressure inside the cabinet and as physics tells us, the air will move (along with the dust) to an area of lower pressure, via the filtered outlet in this case. 

It may appear to be too small to make any noticeable improvement, but I found that it significantly speeds up the rate that the dust clears. On the outside of the filtered outlet I have added a cardboard tube with one end cut at an angle. This is end is placed directly over the outlet hole with the other end faces out of the garage window behind the cabinet. In other words it is a cardboard exhaust pipe and it makes a huge difference in preventing the extracted dust from accumulating in the garage.

 

At the moment everything is held in place with copious amounts of gaffer tape and although it would be great to fabricate something more permanent, I really just want to get blasting, so sod it - I am going to leave it rough and ready!

Chassis paint has arrived! (Mastic 121)

Just received the hard-as-nails paint that I will be using to coat the chassis and various other components:

 

Mastic 121 is a two pack Epoxy paint and is highly recommended amongst restorers (believe me, I did a LOT of internet research before choosing my paint system!). Additionally I purchased some FE-123 Molecular Rust Converter, so that I can thwart any sneaky rust areas that I cannot reach with a wire wheel before applying the top coat. 

Most importantly is the correct mask; the epoxy paint is not too pleasant on the lungs if inhaled. At the recommendation of Rustbuster (I phoned them directly to check this) I opted for the '3M 4251 Gas/Vapour and Particulate Respirator'.

Exciting times ahead....

New repair panels!

Took delivery of a bundle of quality treats from Hooky's Panel Shop today:

• A pillar tool (for door alignment)
• A pillar (3 screw RH)
• A pillar (3 screw LH)
• Screen corner (RH)
• Screen corner (LH)
• M8 weld nuts (x10)

Front Bulkhead and A-post’s bare all!

During the past week I have stripped back the foot-well and bulkhead area of the shell with the drill-mounted wire wheel:

My drill died about halfway through this task (the 3^rd drill casualty so far in this resto), so off I went to the large DIY chain store where I originally purchased it and exchanged it for a brand new one ….ahh, the system works ;-)

It should be noted that the doors have never been particularly well aligned on this car, especially the driver’s side. So, once the wire wheel had made short work of the thick filler layers, I was able to see what was truly going on with those feeble A-posts. The passenger’s side had been repaired in the past using a standard off-the-shelf repair panel, but it looks awkward and somewhat crooked: 

The driver’s side was just patched in a half-arsed way and completely lacks strength, which explains why the door would always drop a couple inches when opened! 

Luckily Hooky’s panel shop make top quality replacements, so I now have some on order along with a handy ‘Door Alignment Tool’, which will allow me to weld the lower door mounting brackets in perfect position. 

I then removed the remnants of the rotten heater channel that was attached to the front bulkhead using a mini grinding disc attached to the Draper Multi-tool: 

I then ground off the hideous repair patches from the other side of the bulkhead: 

I am not sure how much of this metal work will be kept or how much I will eventually cut out, so I may well be taking the long route by spending valuable time carefully removing these old repairs. However, I find it hard to visualise what needs doing and how things should fit back together with these rusty distractions in the way – so for me it feels like a necessary task...

News from the garage

My apologies for the small break in blog posts lately, I have been doing many little odd jobs in the garage and thought it would be most efficient to deliver a round-up post when I had enough news. So, here is a brief overview of the past month of activity....

My glamorous assistant has been dropping by occasionally to continue stripping the shell. Starting to make some real headway at the front end now:

Meanwhile I set about cutting out chunks of rusty bad metal from old repairs that I could no longer stand the sight of:

However, it has recently come to my attention that the front of the car has had a shunt in the past, as there is some buckling and creases along front quarter panels that were not part of the original factory pressings (hard to see from this photo, but it is quite blatant in real life):

I have a feeling that I will end up replacing the front quarter panels entirely, but as my experience and confidence in making these judgement calls is still lacking I shall make this decision at a later date. Even so, I decided to press on and began stripping the passengers side:

As the eagle-eyed of you may gather from the semi-outdoors shots of the shell above, I finally got the rear of the car up on casters! Again, I significantly shortened the width of it to maximise the overall space in the garage:

This one turned out to be more unstable than the front one with a quite a bit of lateral play, so I added some additional support for peace of mind. The shell can now be maneuvered in the garage by one person, however taking in it onto the often muddy terrain outside still requires the assistance of an extra willing person. I am happy though because, with the summer months approaching, I can simply roll the shell outside whenever I need to liberate a bit of workshop space! 

Oh, something I forgot to mention in my previous post; when I was inspecting the state of spare wheel well area I found evidence of an improvised repair using fibre-glass that I was able to pick off in small pieces using my fingers! I am now starting to desensitise to the all the lurking horrors and have accepted that it is all part of the fun of restoring an old car:

The pros and cons of my blasting rig

After a lot of research I decided to go for Aluminium Oxide (60 – 80 grit) as my blasting media. I was able to pick up a 20kg tub locally and added the whole lot to the hopper. I blasted these small inspection hatch pieces to get a feel for it:

I was delighted with the results as the surfaces are amazingly clean and it seems to be gentle to the healthy metal under the rust. Plus, the embossed factory numbers are preserved in amazing condition, something that a wire wheel would have no doubt damaged or partially erased. For a before/after comparison, here is a vent cover from one the heater channels with a thick layer of paint and crud all over it:

After a quick sandblast:

And finally everything gets the usual lick of primer:

However, not all is as good as it seems. There are a couple of annoying problems with my current set-up. Firstly, my little 2.5Hp compressor cannot keep up with the air demands of shot blasting. It has a tiny 24L tank and it is just not enough to hold a sufficient volume of air. In fact, I can only blast for about 8 seconds then I have to wait for it to re-pressurise and this recovery time gets frustrating after a while. Having looked into my options I have identified 3 possible solutions:

1. A more powerful compressor – this would be ideal however for a hobbyist like me this does not make good economic sense because a big compressor that has the spec required is a LOT of cash!

2. Add an expansion tank – I could link a receiver tank to the compressor to increase the overall volume of compressed air at my disposal. This would allow me to a much longer blasting time, but on the flipside the recovery time would be equally longer.

3. Link two compressors in together in tandem – this I feel is the ideal solution. Basically I need to get another little cheap compressor and join it together with my current one with a ‘y’ connector. This would increase the overall tank size and recovery time. Best of all I could set the compressors to kick in at slightly different times (e.g: one starts when the pressure hits 90psi and the other when the pressure dips to 80psi).  

The second issue that I was encountering was the amount of dust being generated which obscured vision a lot quicker than I had anticipated. I think I will rig up a vacuum extraction system at the time I add a 2^nd compressor. In fact, I have an old vacuum cleaner that would be ideal for the task! Stayed tuned...

New toy!

Manged to bag myself this eBay bargain shot blast cabinet over the weekend:

Unfortunately it didn't come with the mesh screen (floor section) and the perspex window was all frosted up, but I thought a quick trip to my local DIY store would cure those minor problems. Unfortunately the shop didn't stock perspex or meshing! However, on the way back to the garage I came across some metal mesh dumped in a bush next to a bus stop - literally the perfect width as well! So, after a quick trim with the angle grinder and the persuation of a hammer to flatten it out, I had it sitting inside the cabinet perfectly snug! 

Now I have just got to get some blast media and it will be good to go (albeit with a slightly frosty viewing window)!  

EDIT (23/05/14): I now have some new Perspex (clear acylic/plexiglass) windows for the shot blast cabinet. I found that it was cheaper to order this stuff as a made to measure item online than it was to purchase a big sheet at a diy store, which would still need cutting down to size! The only real sting was the cost of postage – but I offset this cost by ordering 10 units at once, so this batch should last me some time!