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Reto S |
November 16, 2013, 12:53am |
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It's my understanding that once properly dried and protected from direct, prolonged contact with liquid water, lumber in a tropical climate with average humidity near 90% reaches an equilibrium moisture content near 20%. And 20% moisture content is the threshold for fungi growth according to the US Forest Products Wood Handbook. My opinion is that two months at the threshold for fungi growth is not a concern. Use of a preservative may very well degrade the epoxy bonds and using a varnish will require sanding off the varnish from mating surfaces before gluing. Of course, once an assembly is completed it should be varnished.
Thank you for the additional input. As my workshop has a good climate, I will apply protection after finishing the Max. |
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Reto S |
November 16, 2013, 12:57am |
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Some kinds of anti-fungal treatments will definitely interfere with bonding.
Tom
Tom, your glue and protection process seems to be a good way forward. Unfortunately we have great difficulties importing any chemical products into Thailand. The only glue I have at hand is T88. Thanks for the input. Reto |
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Reto S |
November 16, 2013, 1:02am |
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Hi Reto, The project is looking good.. BTW, It was my concerned too especially in tropic country like Philippines..I did applied wood preservatives followed with polyurethane varnish after assemblies. Phil
Dear Phil Only now I realize that we must have been neighbours in the Philippines (I am a bit slow at times.. ). Have you been member of ACFC? Thank you for your input, will do the same regarding the treatment. If I may ask, what kind of Max did you build and where have you been living? Reto |
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Phil |
November 16, 2013, 10:40am |
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Ace
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Dear Phil Only now I realize that we must have been neighbours in the Philippines (I am a bit slow at times.. ). Have you been member of ACFC? Thank you for your input, will do the same regarding the treatment. If I may ask, what kind of Max did you build and where have you been living? Reto[/quote] Reto, No, I'm not a ACFC member but flown their ultralight twice as checkrides before I made the maiden of Rans S-12 I assembled for a friend in our place in Ozamiz City which I lived. The original T.E.A.M. ultralight miniMAX 1989 Model. Plans-build with rotax 277 on it. .but awaits to be airborne Regards, Phil
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Tom |
November 16, 2013, 12:37pm |
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Dear Reto, Your local distributor/retailer for WEST System(tm) Products is: East Marine Co. Ltd. 23/159 Moo 2 Tambon Koh Kae Phuket 83200 info@eastmarineasia.com http://www.eastmarineasia.comThe person in charge, I think, is Scott Bradley. This is their central address but I think they have stores all over Thailand. Don't be put off by the fact that this is a marine outfit, rather than an aircraft one. Burt Rutan recommends WEST System epoxy products for building his amateur buildable designs and his company Scaled Composites uses the same company's Pro-Set line of post cure heat treated epoxy for their prototype aircraft and spacecraft. WEST System and G/Flex are also sold by Aircraft Spruce. I have used these products since 1977 and highly recommend them. I am not affiliated in any way with the manufacturers or distributors of these products, though I have corresponded with them on many occasions and supplied technical literature to various people connected with the company and its products. Tom |
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Reto S |
November 16, 2013, 4:37pm |
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Dear Phil Only now I realize that we must have been neighbours in the Philippines (I am a bit slow at times.. ). Have you been member of ACFC? Thank you for your input, will do the same regarding the treatment. If I may ask, what kind of Max did you build and where have you been living? Reto
Reto, No, I'm not a ACFC member but flown their ultralight twice as checkrides before I made the maiden of Rans S-12 I assembled for a friend in our place in Ozamiz City which I lived. The original T.E.A.M. ultralight miniMAX 1989 Model. Plans-build with rotax 277 on it. .but awaits to be airborne Regards, Phil[/quote] Phil What a story! I lived at the lake of Taal. When will she fly? Regards Reto |
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Reto S |
November 16, 2013, 4:44pm |
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Dear Reto, Your local distributor/retailer for WEST System(tm) Products is: East Marine Co. Ltd. 23/159 Moo 2 Tambon Koh Kae Phuket 83200 info@eastmarineasia.com http://www.eastmarineasia.comThe person in charge, I think, is Scott Bradley. This is their central address but I think they have stores all over Thailand. Don't be put off by the fact that this is a marine outfit, rather than an aircraft one. Burt Rutan recommends WEST System epoxy products for building his amateur buildable designs and his company Scaled Composites uses the same company's Pro-Set line of post cure heat treated epoxy for their prototype aircraft and spacecraft. WEST System and G/Flex are also sold by Aircraft Spruce. I have used these products since 1977 and highly recommend them. I am not affiliated in any way with the manufacturers or distributors of these products, though I have corresponded with them on many occasions and supplied technical literature to various people connected with the company and its products. Tom
Dear Tom Thank you for your great input and contacts in Thailand. As I understand you prefer West system epoxy over T88. What are the main advantages of G/Flex epoxy compared to T88? Regards Reto |
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Reto S |
November 16, 2013, 4:54pm |
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Dear members Had a productive day today. One more question appeared though: By glueing the next rib I realized that the 1/4 x 1/4" cap stick vary greatly in size. Actually they vary mainly in the width of the cut sides which in turn makes it a bit difficult to glue the gussets flat in place. The first 5 ribs I have build always with the cut side on top (and down), showing the grain structure (see below picture). Now I wonder, if I should have always glued the ribs with the flat side on top and down. Or doesn't it matter at all? In one of the wing drawing details it shows the cut side on top too... Sorry for the complicated way explaining. The picture might make my question more clear. Thank you Reto
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Tom |
November 16, 2013, 6:02pm |
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Dear Reto, I have private messaged you on epoxy products. I can only say what I recommend and discuss characteristics of recommended products. I am not saying that I don't recommend T-88. Tom |
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Ricardo |
November 16, 2013, 11:52pm |
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Videos in UTube: ral1951 Ace
Posts: 2,772
Time Online: 75 days 23 hours 15 minutes
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Here we have over 90% humidity in winter, took me more than 6 years to finish my plane, I epoxy varnished every piece so moisture and fungus will never enter the wood.
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Reto S |
November 17, 2013, 2:23am |
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Here we have over 90% humidity in winter, took me more than 6 years to finish my plane, I epoxy varnished every piece so moisture and fungus will never enter the wood.
Dear Ricardo She looks absolutely stunning.. If not too much of hassle, perhaps you got some more shots from different angels.. It's a great motivation to see her structure beautifully finished.. Thank you for sharing.. Cheers Reto |
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Ricardo |
November 17, 2013, 5:57pm |
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Videos in UTube: ral1951 Ace
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Reto: I used a local epoxy varnish that you should be able to find in your area. That kind of product will last you a life time. It is compatible with T-88. For covering the plane,I used the Stewart syatem and I sanded off fhe epoxy surfaces on the areas where the Stewart glue had to be applied. Here's some more shots of the "naked" plane.
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Tom |
November 17, 2013, 7:38pm |
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Ricardo,
Beautiful work.
Tom |
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Reto S |
November 18, 2013, 2:51am |
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Reto: I used a local epoxy varnish that you should be able to find in your area. That kind of product will last you a life time. It is compatible with T-88. For covering the plane,I used the Stewart syatem and I sanded off fhe epoxy surfaces on the areas where the Stewart glue had to be applied. Here's some more shots of the "naked" plane.
Dear Ricardo Thank you very much for sharing the pictures. What a beautiful work you have done. Considering doing the same, but will use Poly-Fiber products. There is just enough stock of Poly-Fiber in the country to cover 1 plane... Kind regards Reto |
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Reto S |
November 18, 2013, 2:58am |
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Dear members Apologies for posting again a question I had a few days ago... By glueing the next rib I realized that the 1/4 x 1/4" cap stick vary greatly in size and dimension. Actually they vary mainly in width of the cut sides, which in turn makes it a bit difficult to glue the gussets flat in place. The first 5 ribs I have build always with the cut side on top (and down), showing the grain structure (see below picture). Now I wonder, if I should have always glued the ribs with the flat side on top and down (different grain structure, but mainly same width). Or doesn't it matter at all which way to glue? In one of the wing drawing details, it shows the cut side on top too (same as my glueing)... Sorry for the complicated way explaining. The picture might make my question more clear. Thank you for inputs. Reto
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Bob Daly |
November 18, 2013, 2:10pm |
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It does not matter which way the grain is oriented. Try to make the surfaces even so the gussets lie flat. The epoxy will fill a gap so it is not at all critical. |
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Reto S |
November 18, 2013, 3:21pm |
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It does not matter which way the grain is oriented. Try to make the surfaces even so the gussets lie flat. The epoxy will fill a gap so it is not at all critical.
Thank you Bob That is reassuring... Did exactly that... |
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lake_harley |
November 18, 2013, 6:05pm |
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I second Bob's comment about the grain orientation not being critical. I had the same concerns and somehere, maybe here or possibly on another forum, someone linked what I recall to be a EAA tech article stating the grain can be oriented horizontally or vertically. So, per that, for what it's worth, is more reassurance for you.
Lynn |
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superswamper |
November 19, 2013, 12:31am |
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Flight Leader
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Reto, I had the same problem. What I did was to try match up the pieces as I was building each rib. one rib might be a tiny bit wider than others. the main thing is that there pretty flat for the gussets. look at the bright side!! you don't have that problem on the other side!!! Its gets a lot easier as you go, and just when you get it figured out your on your number 24 |
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Reto S |
November 19, 2013, 1:48am |
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I second Bob's comment about the grain orientation not being critical. I had the same concerns and somehere, maybe here or possibly on another forum, someone linked what I recall to be a EAA tech article stating the grain can be oriented horizontally or vertically. So, per that, for what it's worth, is more reassurance for you.
Lynn
Dear Lynn Thank you for the additional feedback. My main concern was/is 2-fold: 1. Gusset glueing (uneven surface), which we solved with mix and match... 2. Grain direction on outer cap sticks (pre-curved one), in my opinion it really does make a difference which way the outer cap stick's grain is oriented. Bending with the grain seems much more logical than bending "vertical" oriented grain. For compression stress with inner sticks I would agree that it doesn't matter. I will continue (like on the picture) glueing all sticks with grain direction visible... Cheers Reto |
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Reto S |
November 19, 2013, 2:19am |
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No apologies, They got off track looking at Ricardos beautiful plane in stick form and forgot to answer your question. I am not a builder but I would agree with Bob above. Personally I (if building) would rather see the gussets lying flat and know I got a good evenly distributed bond. The slight width differences that now would cause a slight difference in the (height) of each rib would seem to be insignificant in the (big picture). I guess you could clamp a bunch of finished ribs together with the bottoms all lined up perfectly and carefully sand of some material from the tops to make them all even by running past a belt sander, but I am not sure even that matters. Would you really even notice on a covered wing that one or another rib is maybe taller by a 1/16th of an inch from the one in the next bay? I doubt it. Plus it's not an F-14 fighter either (LOL). Hopefully that's about the MAXIMUM differences in width (height)we are talking about anyway. Seems obvious right from the start that you are very detail oriented. That's going to be a good thing and I am sure in no time you will be posting some photos as Ricardo has Hopefully you will have time to look over this boards older threads and find or decide what small modifications you might think you would like while you are in the building process. Some things that I have written about & have been talked about and think are worthy of thinking about might be....... separate right & left brakes instead of the single brake lever. Dis-connectable and even separate cables from your pedals to your rudder and tail wheel. Elimination of the single side rod that controls the tail wheel in favor of springs and chains on two sides. A SOLID non teleflex elevator control rod. (or there are some designs that have used control horns and various pivot points and linkages. These are just a few to think about if you have not already. You can find threads on all of these things here on this board if you do some searching. Of course you might as well know right now, anytime you bring up making any changes to the bird you will be getting a lot of posts that tell you to just stick to the plans. And that's TRUE for the most part. But there is always room for improvement & you can find many that have done these (improvements) and are very satisfied with the results. TTT
Dear TTT Thank you for your detailed reply. Yes, I got pleasantly distracted too by Ricardo's beautiful pictures... Regarding the ribs: It wasn't so much of my concern deviating from outer rib dimension. My main concern was/is 2-fold: 1. Gusset glueing (uneven surface when stick grain visible), which we solved with mix and match... 2. Grain direction on outer cap sticks (bottom and pre-curved one). In my very humble opinion it really does make a difference which way the outer cap stick's grain is oriented. Bending with the grain seems much more logical than bending against "vertical" oriented grain. For compression stress with inner sticks I agree that it doesn't matter. Regarding improvements: I share your opinion that any modification which ads to safety is worthwhile considering. Thank you for taking up my earlier question regarding this. By no means it was my intention to suggest the MM is weak or unsafe. It is just a gut feeling that a heavy Eros is much more exposed to stress at certain (attachment) points than the earlier much lighter versions. It looks to me that there has been done very little strengthening (if any) for example where the stabilizer is attached to the fuselage (I didn't have the opportunity to compare for example 1100R plans with Eros plans) Bob did a quick calculation and confirmed the load has increased from 220lbs to 300lbs which is about 1/3. There is still a long way to 500lbs (gussets shear strength). Therefore I will pay extra care/attention to those areas. Thank you for mentioning other areas of interest which have been discussed. I certainly will look them up in the forum to gather more information... Have a good day! Reto |
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Reto S |
November 19, 2013, 2:36am |
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Reto, I had the same problem. What I did was to try match up the pieces as I was building each rib. one rib might be a tiny bit wider than others. the main thing is that there pretty flat for the gussets. look at the bright side!! you don't have that problem on the other side!!! Its gets a lot easier as you go, and just when you get it figured out your on your number 24
Dear Superswamper Thank you for your kind words of encouragement... Rib #6 is almost done. Just hoping that towards #24 I am not running out of width-matching sticks... And yes, the glass is "half full" by the fact "that the other side is flat" ... "Happy" you were suffering with me... Cheers Reto |
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superswamper |
November 19, 2013, 3:00am |
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Flight Leader
Posts: 143
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Reto, I agree with you on grain orientation on the upper and lower cap strips, I did mine the same way. I tried to use all the larger pieces for the caps. My kit was done by John Grabber when it was JDT, I think he cut and planed all the material himself, but I might be mistaken. Not sure how David does it. When I first started I found out the worst mistake you can make is over clamping the material and starving the glue joint. (very important) Do a search on PVC pipe clamps, those things work perfect, you can make a bunch of them for next to nothing. I made some out of 4" and 3" pipe, saves you a ton of money on clamps. And your going to need a bunch of them on your fuse. And they can get into tight places. Jim |
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superswamper |
November 19, 2013, 3:31am |
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Flight Leader
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One other thing you guys were talking about t-88 great stuff. The one problem that I have had is that once the hardener is opened and sits for a few months it turns darker in color, once this happens it takes a lot longer for it to cure. I have glued up pieces and three days later they still felt a little tacky. They eventually harden, but once this happens I always tossed it and bought some more. You got to be careful were you order it from because if it sits on the shelf for a long period of time it could come that way. The first sub kit I got the glue was that way because it was old, thought I was doing something wrong so I ordered a new batch from aircraft spruce big difference! rock hard the next day. If you guys read this and I'm wrong please correct me, this is just my experience here in Florida with very high humidity. Jim |
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Reto S |
November 20, 2013, 1:22am |
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Ace
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One other thing you guys were talking about t-88 great stuff. The one problem that I have had is that once the hardener is opened and sits for a few months it turns darker in color, once this happens it takes a lot longer for it to cure. I have glued up pieces and three days later they still felt a little tacky. They eventually harden, but once this happens I always tossed it and bought some more. You got to be careful were you order it from because if it sits on the shelf for a long period of time it could come that way. The first sub kit I got the glue was that way because it was old, thought I was doing something wrong so I ordered a new batch from aircraft spruce big difference! rock hard the next day. If you guys read this and I'm wrong please correct me, this is just my experience here in Florida with very high humidity. Jim
Dear Jim Great input regarding the T88, clamps and over-clamping. Thank you. I try to have both sides of any two pieces covered with epoxy and wait for a little while before I clamp or staple them. The wood seems to absorb quite a bit. The T88 I use seems to be Ok, but I noticed lately a thin dark brown layer forming in the hardener bottle. In the workshop I keep the humidity around 50% and it looks like the epoxy bonds well under these conditions. As soon I got "stickiness" I will discharge the "off" epoxy too. Have a good day. Cheers Reto |
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flydog |
November 20, 2013, 1:25am |
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Just working from memory here (dangerous : ) Doesnt it say somewhere that T-88 may darken,but is no big deal? The stiky-ness you mention was likely "Amine blush"(common in high humidity), and again, no big deal. |
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Tom |
November 20, 2013, 11:07am |
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For those who might wish to use Gougeon Brothers, Inc. products such as the WEST System(tm) line of epoxy products and their G/Flex epoxy. Without comparing it in any way with T-88 I can say that the hardeners for the WEST System(tm) do tend to darken over time. However the structural properties of WEST System products do not change over quite long periods of time measured in years. I know this from personal experience and from tests which the manufacturer has done on old batches of their products kept for long periods specifically for testing. I can definitely recommend WEST System(tm) for projects that continue over longer periods of time.
Tom |
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Reto S |
November 20, 2013, 3:03pm |
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Trying to get rid of an annoying cold, but making some progress... - Started rib #7 - Horizontal stabilizer ready for glueing - Received Rac T2-7A trim system - 130 hrs into the build Made simple shear and brake tests with cut off wood parts. My T88 seems to be fine (wood always brakes first). Cheers Reto
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Reto S |
November 28, 2013, 4:18am |
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Dear forum members One of my previous questions was related to the area of hinge/bracket attachment with the vertical stabilizer (#14-61). I just came across a MM "AD" which shows that there were concerns in that area from the Team MM too. In the AD the hinge attachment has moved further up. The 2 corner blocks I glued in are re-enforcing both sides, above and below the horizontal rib. Not sure if this "AD" is known to the forum members as nobody has mentioned it. The "AD" is attached below. Cheers Reto
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superswamper |
November 29, 2013, 3:57pm |
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Flight Leader
Posts: 143
Time Online: 18 days 4 hours 1 minutes
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Reto that is correct, attachment point for brace stays to the plans, but you move the hinge up to dimension shown on addendum. I got this with my plans several years back. Jim |
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