View Full Version : Bonding Material
heliguy02
06-01-2009, 06:44 AM
Hello everyone,
I am building a small wood boat with a Yamaha jetski engine and pump drive.
I cut the bottom of the jetski hull out to fit into the bottom of my boat. I am trying to find a good bonding material that will help seal and bond the fiberglass jetski hull to the bottom of my plywood boat. It will be screwed in place also so the material will be more of a sealer than a bonder. I am looking for stuff that is like what the jetski manufactures use to bond their hulls together. If any of you have seen this stuff, it is REAL strong, but stays semi rigid. It does not dry hard and brittle, but it is harder than just window caulk.
Anyone got any suggestions on what I can use and where to get it?
Thanks, Tony
Epoxy, epoxy, epoxy. You don't want a sealant, you want to bond it solidly. Epoxy and fabric, preferably biax.
Duplicate post . . .
rbrooks
06-01-2009, 10:09 PM
Absolutely, epoxy. there are some other bonding agent that will work but epoxy is the best, most available, and most novice friendly. If you seal the wooden part with glass and resin,(epoxy or other) you can bond with a methacrylate glue like plexus or IPS Weld On and several others. These are the types of glue used to build jet skis and even large boats these days. Good luck
Again, epoxy. Nothing, no adhesive comes close to the performance of it in this application.
heliguy02
06-02-2009, 06:18 AM
Epoxy huh? Ok I am glad I asked. I thought a semi flexable bonding adhesive would have been the way to go, but this is my first attempt at doing this so that is why I get advice from the experts.
Thanks guys,
Tony
kistinie
06-02-2009, 12:45 PM
Epoxy yes, but not only
an army research on hull strength to explosions showed that best solution was to first polyurethane glue especially on the sides then over it epoxy as told.
Polyurethane will absorb vibrations and help flexibility before rupture
and any intrusion in wood of bolts or other foreign object is done only with epoxy, polyurethane will not stop water, wood will be rotten.
TeddyDiver
06-02-2009, 12:59 PM
Polyurethane will absorb vibrations and help flexibility before rupture.
Thats what flexible engine mounts are for.. so epoxy:D
Jimbo1490
06-02-2009, 01:30 PM
Epoxy yes, but not only
an army research on hull strength to explosions showed that best solution was to first polyurethane glue especially on the sides then over it epoxy as told.
Polyurethane will absorb vibrations and help flexibility before rupture
and any intrusion in wood of bolts or other foreign object is done only with epoxy, polyurethane will not stop water, wood will be rotten.
There are plenty of flexible epoxy adhesive formulations on the market. Some, like 3M's 2216 are toughened with a CTBN rubber compound. This adhesive exhibits over 100% elongation before breaking.
The word 'Epoxy' covers a wide range of products with varied cured-state properties from extremely hard, with high UTS but brittle all the way to soft and rubbery with moderate strength but outstanding toughness and resistance to breakage.
A laminating resin will work as a glue, but is not optimized for that use. The opposite is true for a 'glue' type epoxy; you could laminate with it in a pinch, but that's certainly not its best use.
Jimbo
kistinie
06-02-2009, 01:32 PM
Yes of course, but this principle allows you to work with low grade products, easy to find and low cost, (this system is also terrific for omega inside hull)
PS: (Low grade = basic, low cost std epoxy & polyurethane)
apex1
06-02-2009, 01:39 PM
Yes of course, but this principle allows you to work with low grade products, easy to find and low cost, (this system is also terrific for omega inside hull)
What please is: "omega inside hull" in your opinion?
So, at the end: ...................EPOXY! and only Epoxy.
M-Sasha
06-02-2009, 04:15 PM
Yes of course, but this principle allows you to work with low grade products, easy to find and low cost, (this system is also terrific for omega inside hull)
Where do you think is the "easy to find, low cost" substitution for Epoxy Mr. smart alec?
If the experts here, PAR, Ike, Apex, say Epoxy for this application, then it is Epoxy. period
Sasha
kistinie
06-02-2009, 05:10 PM
Teddy, to filter the wider range of vibrations it is always more efficient to diversify the materials and have different absorbing level, on several layers, the polyurethane core inside epoxy is a very effective solution to absorb energy.
Apex an sasha
No problemo
I do not care to a point you cannot imagine...Do like you feel
And i do, like i do for many years, as the IFREMER and French army research lab, advice.
Try to be happy and have good time
Nothing against your research Kistinie, but your statement "it is always more efficient to diversify the materials and have different absorbing level, on several layers" flies in the face of the engineering principles involved in the tasks Heliguy02 is attempting.
This exact process has been preformed before and it basically boils down to bonding a GRP part to a wooden part. Mixing dissimilar materials in the joint is just asking for more trouble then necessary. From an engineering view point, you just want a solid, water tight bond, of sufficient strength to exceed the physical limitations of the two adhered materials, which is easily achieved with epoxy and some fabric.
Vibration wouldn't be consideration as the new, resulting structure would be homogenous in nature. Devices are already in place to handle any of the mechanical or airborne vibrations that may be present and both materials are capable of tolerating both.
kistinie
06-03-2009, 12:48 AM
It is not "my" research, i do like this for a long time with great success.
i never said the full epoxy only does not work and is not a good solution
I speak of a core inside fully covered.epoxy part for extra strength.
Ok "often" is better than "always" about vibrations, i agree you can always have exceptions, in general heterogeneous materials enlarge vibration frequency spectrum absorption capacity.
Compare a fresh egg and a cooked hard one, and make it turn or vibrate.
In fact if i were you, i would have try to learn more, to ask more questions about this solution rather than say a kind of no. Its a choice, i respect it.
So, once again sorry to have disturbed, and do like you feel :)
Arrivederci !
Why nobody spoke of methacrylate bonding ?
http://www.scottbader.com/downloads/UK_PDF_Brochures/Adhesives/Crestomer%20Brochure_English.pdf other brands do exist.
The methacrylate are the one that have an elongation at break of 100%. The one at 6% or less are epoxies.
Jimbo1490
06-03-2009, 10:12 AM
The methacrylate are the one that have an elongation at break of 100%. The one at 6% or less are epoxies.
You can tailor epoxy to just about any elongation you want. Some of Shell's 'starting formulations' for flexible adhesives showed 150-200% elongation at break. The 3M 2216 system has 120% and is an off-the-shelf system from a highly reputable company and available worldwide.
Methacrylates work well, especially for NEW rather than repair applications. They are still not as 'wet' as epoxy (judged from droplet contact angles) and are therefore more sensitive to contamination, less forgiving of surface prep and cleanliness. Bonding over surface contamination is an area where epoxy is very forgiving. Also in Shell's 'starting formulations' were adhesives for bonding oily metals that cannot be adequately cleaned. You certainly could not do this with methacrylate.
The methacrylates have cure curves that make them very attractive to manufacturers; they cure fully without any post curing. Also they can bond some difficult materials like UHMW polyethylene better than epoxy. I used 3Ms methacrylate to bond UMMW milled sail track onto the back of a carbon mast. However, I never fully trusted the stuff and so also potted in SS blind nuts and used #8 flush head screws. The data sheet from 3m said I could expect about 900psi lap shear on UHMW initially but that the bond strength would fall to only about 500psi in a couple of years. I probably could have just put screws at the ends and been done with it, but I went and screwed the entire length.
Methacrylate has not yet replaced epoxy, especially for DIY and repair applications, where dirts and mistakes are common.
Jimbo
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