Original Posted By: "Alex Sloan"
Subject: Pietenpol-List: Alodyning aluminum fuel tanksI have a question for all you Pieters who have made your tanks out of aluminum. I've formed all the parts for the tank and clecoed everything together. I want to prime the inside particularly to fend off corrosion. The material is 5052 aluminum sheet, and the traditional method is to clean it up with a scotch brite pad, then degrease with Prepsol or a degreaser, then dunk the parts in Alodyne and then wash. I understand this is nasty stuff and not environmentally friendly, but I have access to the materials and a shop that does it and can dispose of the materials.My question is, should I Alodyne all parts of the tank prior to welding it together, or weld it up except for the bottom, clean and Alodyne the interiors, and then weld on the final section? If there are any recommendations for other fuel-proof primers, I'm open to suggestions on that too.. nothing is written in stone here. Matt Paxton________________________________________________________________________________
Pietenpol-List: Alodyning aluminum fuel tanks
Re: Pietenpol-List: Alodyning aluminum fuel tanks
Original Posted By:
Matt,Having built two metal RV type aircraft I can speak having been there. Allparts of the aircraft had to be protected from corrosion except the fueltanks. I could never find any thing that said to do as you are thinking ofdoing. Mr. VanGrunsvan, designer of the RV series, said not to prime thefuel tanks. I plan to build aluminum tanks for my Piet and will not primethe interior in any way. I will prime only the exterior parts of the tank.My tanks will be rivited and sealed using the great Pro-Seal. I will cleanall mating surfaces and scotch Brite them . I use MEK to clean them beingsure to wear protective gloves. Oil from the finger tips can contaminatethe mating surfaces and perhaps not allow the Pro-Seal to adhere. I willnot slosh the tanks as there are some known cases where the slosh wasattacked by some fuel that apparently contained something beside gasoline.The slosh came loose and created blockage in the fuel system. Pro-Seal, ifapplied correctly, will seal up the tank completely. and rest assured, itwill not come off. Acetone does a great job of cleaning up. I willpressure the tank to 1.5 lbs. of air pressure and test it for leaks usingbubble soapy solution. A blood pressure gage makes a great testing gage todetect leaks. If it holds the pressure on the gage, you are in business. 55reading on the gage relates to 1.5 to 2 lbs. of air pressure. I will alsouse this.Sorry for the long post but you ask a very important question.Alex Sloan----- Original Message -----
Matt,Having built two metal RV type aircraft I can speak having been there. Allparts of the aircraft had to be protected from corrosion except the fueltanks. I could never find any thing that said to do as you are thinking ofdoing. Mr. VanGrunsvan, designer of the RV series, said not to prime thefuel tanks. I plan to build aluminum tanks for my Piet and will not primethe interior in any way. I will prime only the exterior parts of the tank.My tanks will be rivited and sealed using the great Pro-Seal. I will cleanall mating surfaces and scotch Brite them . I use MEK to clean them beingsure to wear protective gloves. Oil from the finger tips can contaminatethe mating surfaces and perhaps not allow the Pro-Seal to adhere. I willnot slosh the tanks as there are some known cases where the slosh wasattacked by some fuel that apparently contained something beside gasoline.The slosh came loose and created blockage in the fuel system. Pro-Seal, ifapplied correctly, will seal up the tank completely. and rest assured, itwill not come off. Acetone does a great job of cleaning up. I willpressure the tank to 1.5 lbs. of air pressure and test it for leaks usingbubble soapy solution. A blood pressure gage makes a great testing gage todetect leaks. If it holds the pressure on the gage, you are in business. 55reading on the gage relates to 1.5 to 2 lbs. of air pressure. I will alsouse this.Sorry for the long post but you ask a very important question.Alex Sloan----- Original Message -----
RE: Pietenpol-List: Alodyning aluminum fuel tanks
Original Posted By: owner-pietenpol-list-server(at)matronics.com
HI Matt,I don't know the definitive answer here, but what I've done is to clean theareas that were to be welded with a commercial cleaner prior to welding,then I intend to take the tank to a commercial opeation in Greensboro, NC,where they can immerse the entire tank in a vat and anodize it inside andout.All of this is probably unnecessary, since 5052 has good corrosionresistance by itself.Jack PhillipsRaleigh, NCWhere NX899JP just got her elevators covered today. Starting on the rudderand vertical fin, then the horizontal stabilizer. -----Original Message-----
HI Matt,I don't know the definitive answer here, but what I've done is to clean theareas that were to be welded with a commercial cleaner prior to welding,then I intend to take the tank to a commercial opeation in Greensboro, NC,where they can immerse the entire tank in a vat and anodize it inside andout.All of this is probably unnecessary, since 5052 has good corrosionresistance by itself.Jack PhillipsRaleigh, NCWhere NX899JP just got her elevators covered today. Starting on the rudderand vertical fin, then the horizontal stabilizer. -----Original Message-----
Re: Pietenpol-List: Alodyning aluminum fuel tanks
Original Posted By:
MattI had some similar concerns building my tank but not corrosion. I worriedabout possible future leaks around welded seams.The welder that put my tank together happend to be into HotRods. He had agatalog from Eastwood Company , 1-800-345-1178 specializing in racing /custom auto etc. Try www.eastwoodcompany.com They have a fuel tanksealer suitable for coating the inside of antique fuel tanks to seal leaks.You can coat the entire tank or as I did, order a pint, enough to seep intoall seams.Dick----- Original Message -----
MattI had some similar concerns building my tank but not corrosion. I worriedabout possible future leaks around welded seams.The welder that put my tank together happend to be into HotRods. He had agatalog from Eastwood Company , 1-800-345-1178 specializing in racing /custom auto etc. Try www.eastwoodcompany.com They have a fuel tanksealer suitable for coating the inside of antique fuel tanks to seal leaks.You can coat the entire tank or as I did, order a pint, enough to seep intoall seams.Dick----- Original Message -----
Re: Pietenpol-List: Alodyning aluminum fuel tanks
Original Posted By: "walter evans"
I would agree not to alodine before welding, because the welding will burnit off where you most want it. Personally, I just prime the exterior with agood self etching primer (Variprime). I have always used Randolph sloshingsealer on the interior and have never had any trouble with it even usingauto fuel, although I have heard stories of it coming off with fuel whichhas alcohol in it. I recently cut open a fuel tank that had sloshing sealerin it over ten years ago -- I couldn't bead blast the stuff off.Gene________________________________________________________________________________
I would agree not to alodine before welding, because the welding will burnit off where you most want it. Personally, I just prime the exterior with agood self etching primer (Variprime). I have always used Randolph sloshingsealer on the interior and have never had any trouble with it even usingauto fuel, although I have heard stories of it coming off with fuel whichhas alcohol in it. I recently cut open a fuel tank that had sloshing sealerin it over ten years ago -- I couldn't bead blast the stuff off.Gene________________________________________________________________________________