Welcome to our resource for MG Car Information.
MG Midget and Sprite Technical - DA Sanders
|I'm planning to start having a go at tidying up some of my paintwork a panel at a time. (The full restoration is a planned a few years down the line).
I've decided that a palm-type DA sander might be useful and wonder what advice you might have to offer.
1) Electric or air driven?
I have a Clarke compressor with a 50l tank. Its displacement is rated at 14cfm so its free air delivery will be less. Most of the air sanders I've looked at require 14 cfm under load. I figure that shouldn't be too much of a problem if I'm only working on one panel at a time and am prepared to stop from time to time for the compressor to catch up but I stand to be corrected. (My creaky joints might appreciate a few minutes rest every so often anyway!)
2) Are there any makes you're happy to recommend or would suggest avoiding? Air driven Sealey and Machine Mart sanders are currently vying for pole position here.
Thanks in advance.
|I have a MM sander and a similarly spec'd compressor. I think you'll spend a lot more time resting than sanding.|
|Dave O'Neill 2|
|I can't comment on makes of sander but if you normally have the compressor on, then maybe get an air tool as it's probably more compact and maybe lighter (no motor) but if you want to go into the garage for the odd half hour here and there, it's quicker to pick up and switch on an electrical tool imv. Also it's easier to drag a cable around than an air hose in my experience.
I recently considered getting an air die grinder for cleaning up welds in awkward places that the angle grinder can't get into but opted for rotary grinding bits for the drill instead. But I have a noisy direct drive 50l compressor which I only use when I have to.
I bought a DA a good few years back (air powered) and spent £80 on it. At that time i had a 100 Litre tank compressor, which went pop and was replaced with a 150 tank unit, which was way better.
A DA is air hungry and will quickly trip a smaller 50 litre unit, but if that is what you have then so be it.
As and aside, my nephew works at a Porsche restorer, and they apparently use both, so i guess that says neither is better than the other in the real world.
All i would add, is the need to have a foam pad between the disc and the sander itself. You may know this of course, but get one if you didn't as it should help you keep the pads flatter on the surface you are attending to.
I would also say, if you go air fed, use the time for when the compressor trips in, to check and un-clog your pad (by using another disc lightly applied over the one on the sander) this reduces the chance of getting pig tails in your work. . . .
hope that helps you along
|If you do electric ...which is what i perfer...Dewalt is the best|
Ps if your stripping paint, i found a can of acetone, some throw away rags, a green kitchen scratchy a throw away plasic scraper and chem gloves will take the paint of in little to no time very effortlessly
|Thanks for the advice - plenty of food for thought and some very useful tips.|
Still not decided which sander to go for yet but thanks for the reminder Prop, I have been intending to start with paint stripper, but there's bound to be some sanding along the way.
I'll be tackling the passenger door first and that has an annoying little dent where the wind blew the garage door onto it and I think filler's going to be the easiest option there!
I too have an air fed DA. My 2.5Hp / %)l tank doesn't keep up at all and even when the sander is still working, as soon as the pressure begins to drop away on the tank the sander no longer has enough power to do much at all with a 6" disc. And that is well before the pump cuts back in.
My belief is that professionals favour air fed DA's only because they already have the compressor equipment installed with suffiient capacity. And tradition comes into it too. Up until recent years electric tools with sufficient torque would have been very heavy and cumbersome to use. Things have changed a lot with portable electric tools and I am sure a current version would be much better these days.
|Colin, I'm currently in the market for an electric DA for the very reasons above. My compressor would never cope with an air one either. Obviously can't comment on the sander yet but I've got a recommendation for the abrasives. We use Mirka Abranets at work and they are fantastic, much better than the stick on type. They are Velcro and as the name suggests a net construction. I use them for hand sanding as well.|
|Here is an amazon link to what i use and Guy is spot on |
Are you going for a show finish or a 20 feet away OK in the paddock competition look?
Sure you don't want to spend the time and money on some class winning performance mod instead...
If you are stripping and repairing, is this time (or when doing other panels rather than the door on your stepwise approach) to check and fix any bodywork welding/repairs? Also do your class rules and the Blue Book rules allow for any seam welding, gussetting and other strengthening combined with lightening (and then having to look at the supension!)? inspiration from Modsports racing midgets? I realise the car is not quite a full monocoque.
|It's beginning to look like I'll be going electric. Thanks for the link Prop - De Walt is certainly on the short list!
Mike - thanks for your comments - it's definitely the 20ft look that I'm going for.
There is still plenty to go at on the performance front. I managed 3rd in my class in the clubs champs this year, an improvement of 4th last year, and I have a several ideas that I'm working on.
The panels are pretty sound, only a small rust hole behind a rear wheel arch, so, at this point, I'm not planning on any welding.
To be honest, I'm ashamed of the body work. The Sprite came with the worst paint job I've ever seen. T-cut and elbow grease made it a bit more presentable, but it doesn't bear close inspection (or even from 20 ft really). When I started hill climbing I stuck the numbers on the doors - but pealing them off just took the paint off too! I bought magnetic panels for the next year - but the magnetism isn't strong enough so I still have to tape them on - and removing that tape pulls even more paint off (has anyone ever found white Frog Tape for sale - I can only find green and yellow).I've no idea what sort of paint the PO used but the boot is covered in pimples, like birds eyes, but different! I left the number panels lying on the bonnet for a couple months last winter and the resulting condensation raised more pimples there too!
There are a couple of bodywork issues I will need to deal with before doing a full re-spray, but that will take me far too long. Starting over the winter and tackling a panel at a time should mean that I can attack the worst bits first and not have the car out of commission for too long at each stage so I can still compete next year.
Just to give you some idea what I'm dealing with, here's a picture of my first target!
|Like i suggested, take it off chemically then sand the it with the DA, so make a smooth bright metal finish
Start off with 100 to 120 grit to get any of the lingering mess off then just keep going finer
Acetone is the active ingrediant in paint stripper so id just buy a gallon of that and do one panal at a time
Make sure you wash the car 1st with a power sprayer and get it super clean then soak a wash rag with the acetone and wash the panal and lay the rag over the panal for a few minutes then you can scrap up the mess, next wash sand with with acetone on a green kitchen scrubby to get the cling stuff off, then wash the panal agian with clear clean water and dry with a a cheap bath towel...wear chem gloves acetone wont kill you, but it will eat your hands over a period of time... it drys out the skins oils, so wash yiur hands every so often and use a good hand cream to protect the skins moisture
But the paint will litterally fall off, when i stripped ped mine years ago, i did the whole EXTERIOR of the car in 2 evening maybe 4 hours in total
Watch the rubber and plastic bits the ace will desolve it also
After its stripped then the DA does a nice job smoothing the metal and getting rid of any snot rockets left over on the surface of the panals
After using your acetone, how do you make sure you have got it all off again and out of the crevices and joints in the metal? You wouldn't want it working its way back to your new paint finish as bubbles and blisters.
|Acetone flashes off fairly fast the warmer the temp the faster it evaporites ... its the main active ingrediant brake cleaner in a spray can with but has added soaps to the mix
Thats why i say put it on a rag and let the rag sit on the panal for a few minutes to soften the old paint... otherwise it will soften the paint and flash off
But water will wash it away easily....its not oily
The big draw back to acetone is its highly flamable so No smokimg
But its common here in the usa at any house paint store
Acetone is also finger nail polish remover, just in small bottles ... so ask the wife or daughter for a sample and they can fill you in on its details as well
Acetone is also in gasoline / petro...but to what percentage i do not know
Good to hear about your hillclimbing this year and plans to keep the car competing round each painting job.
I am hopefully out competing next year - my paint is of similar quality!
Acetone in UK is available here for retail customers for domestic use (I.e. rather than industrial only or laboratory use) from fibreglass suppliers, e.g. http://www.allscotltd.co.uk/SOLVENTS--ADDITIVES-&-SEALANTS/ACETONE-PURE/p-123-455/ &
You can also buy it from retail marine chandlers, but this will often be in small quantities and high prices, hence why I prefer getting it from GRP suppliers (and also used to get materials to fix a GRP car).
Years ago I remember using acetone to dry laboratory glass wear.
PS you could paint a white oblong on the door panel - this would solve any paint matching issues and your number panel should not fall off!
For your door numbers, you could have a sign shop make them up in static cling plastic. You would have to store them in a way that they don't get creased when not on the door.
|C R Huff|
|To add to charlies point... dont use ROUND megnetic signs, from some reason the wind from driving will make them fall off... but rectwngle shape work perfect ... just not racer looking|
The cling matiral is getting very popular ... they call it car wrap, you can have a special design printed on it or just keep it plain in any color you want and they can make it for just a panal or part of a panal or the entire car
A lot cheaper then painting
This thread was discussed between 21/10/2017 and 27/10/2017
This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.