trophy160 Posted June 2, 2013 Share Posted June 2, 2013 I'm about to start stripping the old paint from the Saracen, I bought a Sealey needle gun that frankly I'm not too impressed with (plenty of air from compressor). This is a sample patch I had just removed the loose paint from, I have expected it to take it batch to shiny metal, would this be sufficiently well prepared for a zinc primer now? Quote Link to comment Share on other sites More sharing options...
Gordon_M Posted June 2, 2013 Share Posted June 2, 2013 This is my K-38 trailer as it was being cleaned down. Side and fender are just needle-gunned, underside is untouched. I have a few Sealey tools, but my needle gun is just an add-on to the cheapest air chisel I could find. It was also just the tool for replacing all those rivets. It gets rid of several paint coats and give a clean surface in a single pass. Bigger compressor or better quality gun / head, maybe? At the standard you illustrate you could probably get away with gunning the whole thing down and then sanding the flat areas. Quote Link to comment Share on other sites More sharing options...
trophy160 Posted June 2, 2013 Author Share Posted June 2, 2013 I was expecting a finish similar to your trailer. I'm pretty sure my compressor is OK as the pressure does not bleed away when I'm using the gun, I've got around 20 feet of 1/4" air hose so would have thought that would be OK. I do intend going over it with a rotary wire brush but had hoped the needle gun would do the business. Quote Link to comment Share on other sites More sharing options...
Gordon_M Posted June 2, 2013 Share Posted June 2, 2013 Given the relative sizes ( K-38 v saracen ) I think you need more tool for the job. If I was working on the outside I'd probably use a rotary wire brush in preference to that, then use the needle gun for all the hard-to-reach buts. A good one is a good tool, though, quite part from chisel / riveter advantages. Quote Link to comment Share on other sites More sharing options...
N.O.S. Posted June 2, 2013 Share Posted June 2, 2013 Have you oiled the gun? They do run dry after a while and the effectiveness is then very much reduced. I have a Sealey and squirt a little oil into the air inlet every 20 minutes or so. Quote Link to comment Share on other sites More sharing options...
Hoseman Posted June 2, 2013 Share Posted June 2, 2013 Have you oiled the gun? They do run dry after a while and the effectiveness is then very much reduced. I have a Sealey and squirt a little oil into the air inlet every 20 minutes or so. Or get an inline oiler that goes between the hose and the gun. regulates oil feed into gun. Bout 5-10 quid! On a correct setup you would have the TANK outlet, then FILTER/REGULATOR, then OILER! But dont use the oiler if you are spraying!!!!!! Have a seperate filter/regulator for that!! Quote Link to comment Share on other sites More sharing options...
trophy160 Posted June 2, 2013 Author Share Posted June 2, 2013 Yes I have been skirting a few drops of oil into the scaler periodically, perhaps I'll just reserve it for the fiddly bits and use the wire brush elsewhere. Quite honestly, the paint is so poor it is pretty easy to get off. Quote Link to comment Share on other sites More sharing options...
Jerrykins Posted June 2, 2013 Share Posted June 2, 2013 I used the larger Machine Mart needle gun to 'do' a Queen Mary trailer, it took months but did the business. I don't know about the Sealey gun but mine has a choice of three stroke lengths, the long one being best which uses more air, thankfully I've got a large compressor. Good luck. Jerry Quote Link to comment Share on other sites More sharing options...
Lauren Child Posted June 2, 2013 Share Posted June 2, 2013 That doesn't look as clean as it normally does when I've been needle gunning. What needles have you got loaded? Chisel tip work well. I can recommend these guys and gals - http://www.trelawnyspt.com/category/126-needle-and-chisel-scalers.aspx Quote Link to comment Share on other sites More sharing options...
trophy160 Posted June 2, 2013 Author Share Posted June 2, 2013 This is the model I have, perhaps it's just not a very good one http://www.tooled-up.com/artwork/ProdPDF/SA50.pdf Quote Link to comment Share on other sites More sharing options...
Gordon_M Posted June 2, 2013 Share Posted June 2, 2013 The needle scaler head is exactly the same as the one I'm using, however my air chisel is a bit more chunky than the one in that image. Quote Link to comment Share on other sites More sharing options...
Jerrykins Posted June 3, 2013 Share Posted June 3, 2013 This is the model I have, perhaps it's just not a very good one http://www.tooled-up.com/artwork/ProdPDF/SA50.pdf This is the beastie I use http://www.machinemart.co.uk/shop/product/details/cat51-air-needle-scaler. I've had it about 5 years and gone thro' a couple of sets of needles. Needs lots of air though, no complaints with it. Jerry Quote Link to comment Share on other sites More sharing options...
ruxy Posted June 3, 2013 Share Posted June 3, 2013 (edited) Title Re: Paint removal - needle gunning -------------- A needle gun is useless for removal of good sound paint, you are expecting too much off the wrong tool. You need rust scale between sound metal and the paint. You can with chisel points clean to SIS Sa2.5 / 3 (mechanical means - because the standard allows the option) BUT it is obviously going to take much much longer. Normally you would stop short and sweep blast - if you require white metal. With the right primer - you hardly need obtain white metal standard in any case , you would aim for "near white metal" - abt. Sa2.5 / 3 . Blast cleaning rust is far quicker than blast cleaning off sound paint, unless you have the very best gear available. Often a matter of interpretation - most often not in ideal place / circumstances. Edited June 3, 2013 by ruxy amd. Quote Link to comment Share on other sites More sharing options...
trophy160 Posted June 3, 2013 Author Share Posted June 3, 2013 OK, you say You need rust scale between sound metal and the paint so probably my sample preparation is not too far from where I need to be. I've also emailed the photo to the paint supplier/manufacturer to seek their view. Clearly it is a balance between preparation becoming a lifetime job and doing it poorly and having to repeat in a year or two. Quote Link to comment Share on other sites More sharing options...
ruxy Posted June 3, 2013 Share Posted June 3, 2013 Some primers are intended to key on better to a "flash rust" or a bit of mixed surfaces - rather than white metal, probably you should enquire about this. Quote Link to comment Share on other sites More sharing options...
utt61 Posted June 3, 2013 Share Posted June 3, 2013 A "needle gun" is really a needle scaler, and the clue is in the name - it removes scale, rust and loose paint. On sound paint is it is generally wasted effort, although it will tend to remove brittle paint that is not adhering well. If you have a large area that you are going to needle scale, then don't bother with the cheap small scalers. Trelawny make probably the best readily available ones, I use one of these - http://www.trelawnyspt.com/products/25-pistiol-grip-scaler.aspx - and is is excellent. Trelawny supplies needles with different shaped tips for different applications too (one of the problems with el-cheapo scalers is that the tips are all blunt and stay that way - needles are consumables). The use of low-vibration tools (such as the one linked to above) is also highly recommended, eight hours with a cheap tool can leave lasting nerve damage in your hands. If you can get them, use vibration-reducing (gel filled) gloves. A wire brush, especially a twisted cup brush in an angle-grinder, is generally good for removing most surface coverings but will melt some paints and bituminous coatings and smear them all over the place, rather than shift them. Such coatings are generally better removed by scraping (very tedious indeed). Also, a wire brush will often leave a burnished bare metal surface which is not good at all for paint adhesion - a roughened surface - needle scaled or blasted - is much better for long term durability. Best of all is blast cleaning, and the best blast cleaning is a wet blast (which might be better named damp blasting as it is really air blasting with wet media, not water blasting). This is much less messy and allows very good control of surface finish. Unfortunately wet blast equipment tends to be pricey and not DIY and not many contract blasters offer it. See http://www.quillfalcon.com/ for about the most portable and affordable equipment. I am told but have no personal experience of this, that wet blasting is less likely to destroy thinner material than dry blasting. My preferred refinishing system for heavy equipment is wet blast (where practicable) or needle scale (where blast cleaning is not practicable) to get to bare metal wherever there is loose paint, heavy scale, or rust. If there is sound paint that cannot be left (eg too many layers), blast or chemical strip to bare metal. Any bare metal is them given a a phosphoric acid wash, then prime, undercoat and paint in the usual way. The result of this will exceed North Sea oil industry adhesion standards. If there is sound paint, then there is generally no point removing it, in which case a rub down and overpaint is generally sufficient. Also, without wishing to sound like an H&S prodnose, do bear in mind that much of the old equipment we love to restore may have lead-based paint on it, so take steps to avoid inhaling the dust. Quote Link to comment Share on other sites More sharing options...
ruxy Posted June 3, 2013 Share Posted June 3, 2013 (edited) ---------- This was a tester on a cheap , obsolete Bromwade Compair "Automotive" range , maide in Taiwan , sort of copy of a Trelawney. I normally use expensive Swiss manuf. anti-vibe scalers. Crusty rust but under hard on ,but also some sound paint that was harder to bray off , I allowed 15 min per wheel inc. a quick go over with P40 production paint. Performance almost as good as a true industrial scaler , for 1.1/2 hours work - I would prefer to do it that way as setting up for shot-blasting & clean up after would take longer. My moto - never blast if you can needle. btw , don't worry about rubber tyres the needles just bounce off (same as shot) LoL Edited June 3, 2013 by ruxy btw Quote Link to comment Share on other sites More sharing options...
ArtistsRifles Posted June 4, 2013 Share Posted June 4, 2013 Out of curiosity - what about noise level and ear protection when using a needle gun/scaler????? Quote Link to comment Share on other sites More sharing options...
trophy160 Posted June 4, 2013 Author Share Posted June 4, 2013 Perhaps because mine is a bit pathetic, the noise (on the armour) is not that bad, does not 'hurt' my ears without ear muffs Quote Link to comment Share on other sites More sharing options...
mike65 Posted June 4, 2013 Share Posted June 4, 2013 Out of curiosity - what about noise level and ear protection when using a needle gun/scaler????? Yes can strongly recommend ear protection for yourself and most of the road. Quote Link to comment Share on other sites More sharing options...
paulbrook Posted June 4, 2013 Share Posted June 4, 2013 I love the pic of the invisible man with the wheel and needle scaler................. Quote Link to comment Share on other sites More sharing options...
redneck Posted June 4, 2013 Share Posted June 4, 2013 Perhaps because mine is a bit pathetic, the noise (on the armour) is not that bad, does not 'hurt' my ears without ear muffs It doesn't need to hurt to be doing damage;) http://www.hse.gov.uk/noise/ And HAVS is becoming a big problem in industry now http://www.hse.gov.uk/vibration/hav/yourhands.htm Don't mean to be safety nanny but I deal with this stuff on a daily basis. Personally I would use media blasting or wire brush wheels for rust removal and scotch-brite wheels for paint. Quote Link to comment Share on other sites More sharing options...
griff66 Posted June 5, 2013 Share Posted June 5, 2013 no ear protection jesus whilst doing my ferret with needle gun it was soft foam ear plugs and eardefenders and it was still bad its like driving a ferret with no ear protection might be tolerable for a few miles then the gearbox noise really starts to get to you. Quote Link to comment Share on other sites More sharing options...
utt61 Posted June 5, 2013 Share Posted June 5, 2013 Out of curiosity - what about noise level and ear protection when using a needle gun/scaler????? Ear protection is definitely required, especially if working in enclosed spaces! Eye protection and dust protection is also essential. Some years ago I needlegunned all seven wheels from my Bedford "O"-type and the biggest problem I had was that they "rang" like church bells when gunned! It really is worth taking extra care with ear, eye, and lung protection, as well as HAVS. You only get one chance. There is no point restoring the vehicle of your dreams if doing so cripples you. Quote Link to comment Share on other sites More sharing options...
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