Original Posted By: "Gene Rambo"
The discussion on laminating struts has touched on glue/adhesives to be used, or that could be used. When building the aircraft, using the two part epoxy adhesives (T-88) is a little cumbersome. What about single stage poly urethane adhesives/glues, i.e. Gorilla Glue, Titebond? Has anyone used these, with what results? There are mixed reviews on this subject: Fine Woodworking (August '07) and woodgears.ca/joint_strength/glue.html . I am sure there are other reports both supportive and contradictive.I have tested Gorilla Glue with aircraft spruce and plywood, spruce long grain to long grain and butt to long grain and cross grain: with proper usage, the wood breaks before the glue bond. That is, wood grains come off with the break.Hope this does not cause any consternation!Ray Krause________________________________________________________________________________
Pietenpol-List: Sky Scout.."Glue" question?
Re: Pietenpol-List: Sky Scout.."Glue" question?
Original Posted By: Ray Krause
One problem with gorilla glue is that it has not been tested over time. Yes, a glue joint is strong, but in ten years? twenty? after repeated temperature changes?? Stick with the known glues, they are not all that expensive.Gene ----- Original Message -----
One problem with gorilla glue is that it has not been tested over time. Yes, a glue joint is strong, but in ten years? twenty? after repeated temperature changes?? Stick with the known glues, they are not all that expensive.Gene ----- Original Message -----
Pietenpol-List: Sky Scout.."Glue" question?
Original Posted By: santiago morete
Re: Pietenpol-List: Sky Scout.."Glue" question?
Original Posted By: H RULE
My experience with Gorilla Glue is that it requires a very precise clamping pressure and no gaps to make a strong joint. To much pressure and you starve the joint & that's where it fails. Too little pressure or gaps and you get foaming with zero joint strength. Also, as Gene says, there's no history yet, so it's impossible to say if it will hold up.Titebond 3 is more forgiving but you still need a good wood-wood fit and the right clamping pressure. Compared to epoxy, it has a much lower gap strength, but better than Gorilla. Given that it's based on much older chemistry/technology than Gorilla Glue, I'd guess it will last about as long as it's older white glue (Elmer's) predecessors i.e. a long time in a protected environment. Whether or not it's truly waterproof, and therefore able to retain strength, in an unprotected environment for a long time is also an unanswered question.I would not use either glue in a structural situation, although I think that would be an interesting experiment for Titebond 3, just not a flying experiment at this point ;)Kip GardnerOn Feb 25, 2010, at 9:57 PM, Ray Krause wrote:> The discussion on laminating struts has touched on glue/adhesives > to be used, or that could be used. When building the aircraft, > using the two part epoxy adhesives (T-88) is a little cumbersome. > What about single stage poly urethane adhesives/glues, i.e. Gorilla > Glue, Titebond? Has anyone used these, with what results? There > are mixed reviews on this subject: Fine Woodworking (August '07) > and woodgears.ca/joint_strength/glue.html . I am sure there are > other reports both supportive and contradictive.>> I have tested Gorilla Glue with aircraft spruce and plywood, spruce > long grain to long grain and butt to long grain and cross grain: > with proper usage, the wood breaks before the glue bond. That is, > wood grains come off with the break.>> Hope this does not cause any consternation!>> Ray Krause>>________________________________________________________________________________Date: Fri, 26 Feb 2010 04:25:04 -0800 (PST)
My experience with Gorilla Glue is that it requires a very precise clamping pressure and no gaps to make a strong joint. To much pressure and you starve the joint & that's where it fails. Too little pressure or gaps and you get foaming with zero joint strength. Also, as Gene says, there's no history yet, so it's impossible to say if it will hold up.Titebond 3 is more forgiving but you still need a good wood-wood fit and the right clamping pressure. Compared to epoxy, it has a much lower gap strength, but better than Gorilla. Given that it's based on much older chemistry/technology than Gorilla Glue, I'd guess it will last about as long as it's older white glue (Elmer's) predecessors i.e. a long time in a protected environment. Whether or not it's truly waterproof, and therefore able to retain strength, in an unprotected environment for a long time is also an unanswered question.I would not use either glue in a structural situation, although I think that would be an interesting experiment for Titebond 3, just not a flying experiment at this point ;)Kip GardnerOn Feb 25, 2010, at 9:57 PM, Ray Krause wrote:> The discussion on laminating struts has touched on glue/adhesives > to be used, or that could be used. When building the aircraft, > using the two part epoxy adhesives (T-88) is a little cumbersome. > What about single stage poly urethane adhesives/glues, i.e. Gorilla > Glue, Titebond? Has anyone used these, with what results? There > are mixed reviews on this subject: Fine Woodworking (August '07) > and woodgears.ca/joint_strength/glue.html . I am sure there are > other reports both supportive and contradictive.>> I have tested Gorilla Glue with aircraft spruce and plywood, spruce > long grain to long grain and butt to long grain and cross grain: > with proper usage, the wood breaks before the glue bond. That is, > wood grains come off with the break.>> Hope this does not cause any consternation!>> Ray Krause>>________________________________________________________________________________Date: Fri, 26 Feb 2010 04:25:04 -0800 (PST)
m =0A>Sent: Thursday, February 25, 2010 9:57 PM=0A> Pietenpol-List:
Original Posted By: Jeff Boatright
Re: Pietenpol-List: Sky Scout.."Glue" question?
Original Posted By: Kip and Beth Gardner
Kip,I agree about the "gap filling" feature of Gorilla glue. If the joint is not tight, the filler is very weak and does not serve as a bond. But in the areas of true contact, the joint seems to be very strong. As far as clamping goes, it seems take a lot of squeeze pressure to squeeze out enough glue to cause "starvation" because the glue foams in between the joint. I think the foaming creates enough pressure to impregnate the wood. In my "tests", where I glued aircraft plywood to spruce (as in gussets) and used 5/8" brads (from a brad gun) and no clamps, there is always significant wood failure, not joint failure. Sometimes the outer veneer of the plywood separates and sticks to the spruce!You and Gene are correct, there is no history proving the longevity of the bonds. Please note that none of my "tests" are scientific nor calibrated. They are only based on observation of the wood breaking before the bond. I plan to place some of the bonds in water and organic solvents to see if they weaken.As an interesting side note: I have been looking for a small bead to place in the fuel sight tube on my Waiex so I can more easily see the fuel level. I have found nothing that will both float and not dissolve. One day I had a bright idea to try some of the foam from the Gorilla Glue that had dripped on the work bench. After about 7 days, it was still floating and not dissolved (the fuel evaporated!). It also floated in turpentine for over a month, is still floating and still intact!Ray Krause ----- Original Message -----
Kip,I agree about the "gap filling" feature of Gorilla glue. If the joint is not tight, the filler is very weak and does not serve as a bond. But in the areas of true contact, the joint seems to be very strong. As far as clamping goes, it seems take a lot of squeeze pressure to squeeze out enough glue to cause "starvation" because the glue foams in between the joint. I think the foaming creates enough pressure to impregnate the wood. In my "tests", where I glued aircraft plywood to spruce (as in gussets) and used 5/8" brads (from a brad gun) and no clamps, there is always significant wood failure, not joint failure. Sometimes the outer veneer of the plywood separates and sticks to the spruce!You and Gene are correct, there is no history proving the longevity of the bonds. Please note that none of my "tests" are scientific nor calibrated. They are only based on observation of the wood breaking before the bond. I plan to place some of the bonds in water and organic solvents to see if they weaken.As an interesting side note: I have been looking for a small bead to place in the fuel sight tube on my Waiex so I can more easily see the fuel level. I have found nothing that will both float and not dissolve. One day I had a bright idea to try some of the foam from the Gorilla Glue that had dripped on the work bench. After about 7 days, it was still floating and not dissolved (the fuel evaporated!). It also floated in turpentine for over a month, is still floating and still intact!Ray Krause ----- Original Message -----
Re: Pietenpol-List: Sky Scout.."Glue" question?
Original Posted By: H RULE
Yes, it expands 3-4 times its volume. If the joint is not clamped or nailed, the joint will separate and be very weak. A spruce to spruce joint with a plywood gusset nailed with a brad gun is almost impossible to get apart!Ray Krause ----- Original Message -----
Yes, it expands 3-4 times its volume. If the joint is not clamped or nailed, the joint will separate and be very weak. A spruce to spruce joint with a plywood gusset nailed with a brad gun is almost impossible to get apart!Ray Krause ----- Original Message -----
Pietenpol-List: Sky Scout.."Glue" question?
Original Posted By: Jim Markle
Re: Pietenpol-List: Sky Scout.."Glue" question?
Original Posted By: Ray Krause
For what it is worth some RAG Wing aircraft builders have used Excel glues with some success:http://www.excelglue.com/under the fuselage chapter the results can be viewedhttp://homepages.paradise.net.nz/wilsonnz/notehttp://homepages.paradise.net.nz/wilsonnz/Miscellaneous/notes1.jpgMichael in Maine----- Original Message -----
For what it is worth some RAG Wing aircraft builders have used Excel glues with some success:http://www.excelglue.com/under the fuselage chapter the results can be viewedhttp://homepages.paradise.net.nz/wilsonnz/notehttp://homepages.paradise.net.nz/wilsonnz/Miscellaneous/notes1.jpgMichael in Maine----- Original Message -----
> Pietenpol-List: engine run up
Original Posted By: santiago morete
Pietenpol-List: Tailwheel & shimmy
Original Posted By: santiago morete