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Post by baronbeeza on Jul 5, 2015 12:39:27 GMT 12
The Tomahawk has to be one of the easiest I have struck. This is another member's project he has been doing for a few weeks. The flight controls and tail had previously been removed and then stripped and painted over the last few weeks. www.sea2sky.co.nz/Aviation.asp Last weekend we went down to the hangar and pulled the wings ready for stripping this weekend. A few pics showing how quick and easy some of these jobs are. One wing was taken off the trailer for stripping Friday night. The other wing went down midday Saturday. Friday night's wing Saturday's wing just minutes after being removed from the trailer. The owner is basically doing the work alone with just a little assistance from me. As the aircraft has been sitting for a while this is by far the easiest way for me to do the inspection. It is also an opportunity to spruce the machine up with new hardware and the likes. I think he has a vision of it ending up similar to this pic. It will be interesting to see how it compares. He was talking about having the primer on before the end of the weekend but I know he will be spending more than a few hours getting the stripping done completely. The PreKote and Primer doesn't take long to apply afterwards though. Two days to strip and repaint both wings may just be a little too optimistic. We are only working weekends so it may be another week yet. The aircraft is in a hangar at an airfield about 100 Km away so the fuselage will just wait until the repainted (and reassembled) wings are taken back down. The fuselage will come back on the return trip. www.planespotters.net/Aviation_Photos/photo.show?id=500311"> *** EDIT *** Well there we are. Those pics are just in and he is saying that they are both in the same state. Just the ribs and other minor clean-up work before the PreKote scrub. The scrub would take one man about a hour to do both wings. They could then go into the booth and with the heat on they would dry quickly. You would probably be spraying the Primer on about 4 to 16 hours later. One guy could conceivably completely strip and paint both wings in a weekend then if he put his mind to it. In this case he is talking about doing other things on Sunday. www.sea2sky.co.nz/Aviation.asp"> www.prekote.com/"> www.paintcenter.org/rj/jun05k.cfm"> It all started when this girl said "This is easy peasy, I will show you how !"
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Post by baz62 on Jul 5, 2015 16:09:05 GMT 12
Presume the paint booth is heated? Mind you today (at least here in Christchurch)it's been quite tropical. No real issues hiding under the paint then? Do you have to do any NDT inspection on the wing mount points?
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Post by baronbeeza on Jul 5, 2015 17:16:26 GMT 12
The paint will go on in a heated booth with full ventilation etc. That is the quickest part of the whole job anyway so they are not in the booth long. The PreKote is scrubbed in with scotchbrite pads and then hosed off. The critical part is probably about that time as the water has to be completely gone but no dust or contaminants allowed to settle. Again the booth is ideal for that as the parts can be taken in once drip dry and the booth is warm and clean for the drying and getting ready for the paint application. I think a minimum of 4 hours and perhaps a max of 20 or so before the Strontium Chromate primer goes on. The Chromate is in the primer and as such the other Chromate treatments such as Alodine are eliminated. There are no mandatory inspections on the Tomahawk wing as it is basically problem free. It would be rare to hear of cracking or corrosion issues, indeed I have never heard of any. The Cessna wings corrode terribly of course and the Cherokee has the SB 1006 seven year spar inspection. www.barteltaviation.com/assets/Uploads/pdf/PiperSB1006.pdfThe beauty of this particular airframe is that it was completely stripped and repainted previously. While the paint didn't last the distance the rest was done well and there is basically zero corrosion to deal with. It was a case of what you see, you get.. Very easy when you can see right through the paint and not have to second guess numerous touch-ups and the likes. The Tomahawk took a wing life of 11,000 hours to get fast track certification. There is now a STC to extend that life out to something like 18,000 hours and part of that deal is a NDT inspection before the kit is fitted. Again I am not aware of any issues. The wing is super strong and does all the work. The fuselage just sits on top of it and is basically held in place by one 3/8" bolt each side. The rear spar drag brace has a 3/8" bolt and there is an additional bolt under the console to transfer the seat rail load back onto the wing. It is only a 3/16" mother. You may be able to see the flange where the wing attach bolt passes in the pics. There is a boss on the spar web and some substantial fittings on the longeron. The Tomahawk comes apart so easily as the cables, pipes and electrics all have quick disconnects. Even the flap torque tube is just unbolted and shoved up inside the wing out of the way. A couple of guys could do a wing separation in 4 hours or so. You could imagine the fun in trying to strip and repaint the wing with it in-situ. You can see the other brackets in the centre of the upper spar cap also. So that is it, just 3 bolts each side. The action here is fitting a piece of timber between the rear spar tabs and bolting it up to give the wing assembly some rigidity prior to attempting to move it.
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Post by baronbeeza on Jul 11, 2015 17:13:35 GMT 12
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Post by craig on Jul 11, 2015 21:36:55 GMT 12
Wish we had a set up like this down here.
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Post by baronbeeza on Jul 11, 2015 23:53:00 GMT 12
I think the booth is a little over 20' long Craig. The wings are 17' plus a little less with the tips removed. The fuselage will be a little longer at around the 20' mark but it can go in on the diagonal if necessary.
With it being a Saturday job the booth is available but only for a few hours. That is all that is required for the drying and then spraying the few coats on. This is also where the Auster mover comes in handy. Indeed it was built for jobs such as this. The Tomahawk is just so easy though, even compared to the Cherokee. Easy to work on, light and easy for a couple of guys to lift the major parts about.
We are working some distance from the aircraft hangar but by doing the job in stages it will eventually all be sitting back in the hangar just waiting for the reassembly. The other advantage is that the machine was flying until recently. All the bits were there, or at least one would hope they were.
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Post by baronbeeza on Jul 25, 2015 19:07:17 GMT 12
Another Saturday, another step. He has finished painting the wings themselves. Next will be to get the flight controls and small stuff ready for prep and priming etc.
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Post by nzjet on Jul 25, 2015 19:35:11 GMT 12
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Post by baz62 on Jul 25, 2015 20:20:45 GMT 12
Looks great,look forward to seeing the finished product.
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Post by baronbeeza on Jul 25, 2015 20:50:05 GMT 12
The undercarriage legs on the Tomahawk are spring steel. Just like we have with the Cessna aircraft with similar there will be a requirement that the legs are mechanically stripped and not by the use of chemicals. There is a danger of Hydrogen embrittlement and a broken leg on landing could completely ruin your day. The modern strippers are easy to use and have very few hazards compared to those commonly in use just a decade ago but we still have to be careful. This machine is in remarkably sound condition which has meant minimal time having to do corrosion repairs or deal with cracking or other issues. Indeed the Tomahawks seem to fare rather better than the Cherokee in that respect.
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Post by baronbeeza on Jul 26, 2015 7:04:38 GMT 12
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Post by baz62 on Jul 26, 2015 12:36:10 GMT 12
That should look very smart. Probably be the first PA38 to have this colour scheme? (In NZ at least?)
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Post by baronbeeza on Jul 26, 2015 13:44:52 GMT 12
Yes, thanks Baz. The first Cherokee above is of a sim version of an older Cherokee 180. Even the blunt nosed 140 may look reasonable in such a scheme so I am sure we will be seeing a few Cherokees looking similar soon. The Tomahawk should look ok but it all a bit of a design unknown at the moment. The PA38 is naturally a bit more curvey than the Cherokee so may even look better. I am not sure if I have posted the following on here before. It will basically be a copy and paste of one I did recently to a guy with a tatty Cherokee. You only need the aircraft to be shiny where people are going to see it as they taxi past. It would look just like any other aircraft on the lot to the average pilot. There would be many aircraft in the world that have just had a series of touch-ups applied over the original paint for the last 40 years. On the other hand we do have this option also... Before and after pics. This was advertised in the States before Xmas. Paint POOR PAINT Interior SEATS GOOD, PLASTIC PANELS AVERAGE FOR AGE Price (in USD) $15,000 Year 1979 Total Time 1,799 hrs Time SMOH 88 hrs Single owner. Mode C transponder. VOX intercom. Standard inst. The plane has never been hangared but the canopy has always been covered. Plexiglass in very good cond. Poor paint. The wing tips and gear fairings have been replaced. There are tail fairings that should be replaced. The inside plastic panels are indicative of its age. The tires a in good condition. The propeller was overhauled when the engine was The new owner bought this before Xmas. He now has a smart looking machine, less than 2,000 total time and with a freshly overhauled engine. Stripping off the old paint was probably just as easy as what we encountered with similarly worn paint. $300 for 15 litres of stripper. Many owners are content with starting their repaint in this manner. <a href="http://www.abpic.co.uk/search.php?q=OO-IWA&u=reg">http://www.abpic.co.uk/search.php?q=OO-IWA&u=reg</a> A Google of that registration should unearth some before and after pics. **** EDIT **** I should perhaps add that you may struggle to find a 2000 Hr Tomahawk in NZ. The youngest I can remember flying here had 390 hours at the time but needless to say that it was some years ago now. The owner of that one has done a good job and will be well pleased with himself. This aircraft will be a looker from just a few metres. It would be one of the less expensive flying machines to boot. Cheaper than a similar homebuilt I think. Think Jodel D11.
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Post by baz62 on Jul 27, 2015 12:41:09 GMT 12
2000 hours is pretty low for a Tomahawk. Yes that scheme would look good too. When do you think the final paint goes on would love to have a look. Is she going to be based at Ashburton or Rangiora?
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Post by baronbeeza on Jul 27, 2015 14:09:19 GMT 12
The 2000 hour Tomahawk was the one in the States and the new owner obviously had plans for it from the get-go.
The airframe hours don't seem to make much difference to the condition, or value, so much it would appear anyway. The wing life being the issue there but even a 8,000 Hr Tomahawk has 3,000 hrs remaining which a private owner is never going to see out. I am sure Baz can tell of of Austers with 3,000 hrs total time and they must be close to 100 years old now.... I have an 11,000 hour Tomahawk here and it flies the best of any I know. Indeed the best by far.
The time to have a look will be when the fuse is having the last of the paints applied. I will give you a ring Baz closer to the time.
Indeed on that, we have used less primer than I expected so I am in the very fortunate position of having a few kits of the Strontium Chromate primer surplus. It is not easy to get here and some paintshops have had to import it especially. The helicopter paint shop at Wanaka is using the same method as me. If any members here are looking at a pretreatment and primer alternative then I should be able to consider a deal. It is ideal for Alclad and 2024 as you skip the messy Alodine and acid etch stages. You just need to scrub a few dollars of PreKote on instead.
These aircraft will be based wherever hangarage is available and may even be scattered about a bit.
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Post by baz62 on Jul 27, 2015 16:06:22 GMT 12
I am sure Baz can tell of of Austers with 3,000 hrs total time and they must be close to 100 years old now.... Ha ha not quite. yes Austers do seem to hang around, hidden away in hangars and flown on occasion or flown a lot. Then the ones that seem to disappear mainly because they need fabric replaced cos its 100 years old or the engine needs a major overhaul and lo and behold they either can't afford it or it's more than the aircraft is worth. I rememeber Greg Macdonald telling Murray Vincent (then owner of J5 AXJ) on no account to remove the wings as part of a tidy up. In his words "the bloody thing will end up in bits for 10 years!" Maintain and fly regularly was his advice unless something major needs doing. AXJ is still flying with her new owner.
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Post by isc on Jul 27, 2015 22:45:23 GMT 12
Another Auster that gets a regular outing around here is ZK-AYU, good to hear a Gypsy Major every now and then. isc
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Post by baz62 on Jul 28, 2015 12:36:14 GMT 12
Charlies Auster does get a good airing doesn't it? I forgot to ask was the red paint on the PA38 a repaint or factory?
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Post by baronbeeza on Jul 28, 2015 12:53:19 GMT 12
The red Tomahawk had been repainted about 15 years ago from memory. The modern paint stripper eats right through the paint and works from the metal back, not trying to grind through successive layers like the old stuff. As you probably saw the red had basically weathered away in many places but the primer had certainly done it's job.
The stripper works well on most surfaces but sometimes can go a little gooey with some types of paint. It just means a little more mechanical scraping and then a repeat application when that occurs. Normally most of the stuff just waterblasts off.
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Post by isc on Jul 28, 2015 21:00:27 GMT 12
Can't remember what the stripper was that Rex Aviation used back in the 60s (don't think it had a name)I remember a salesman trying to sell us stripper, and giving a demo of his, we then gave him some of our paint work, his barely touched it, then we had a go with ours, a few seconds, and off cam the paint. Sorry rambling. isc
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