Building - glue recomendations please.

Quoted post said:

Originally posted by reply
Hi all,

I've been researching recumbent for a while now and have decided that the only way I am going to get
bunt is to mae something myself. I currently do a 13 mile each way commute on a mountain bike with
all the pain that implies. After looking about I decided a trike was the way to go.

I will be using 3 children's mountain bikes for most parts. My local second hand shop will sell me 2
for £25 the pair so that's a good way there. I have a scaffolding pole (I know - heavy) that I will
be using a length of for the boom. I plan to attach a rear triangle from one of the bikes into a
suitably cut/shaped recess and mount the two front forks, via arms in a "conventional" cruciform
arrangement. This will allow me to use ordinary front wheels.

There are many compromises in there (to keep the price down) such as weight (I'd rather be heavy
than un-reliable) and the same size back wheel will cause a less comfortable ride than a larger
one but there you go. The idea is to see if I can get something that works and improve if it isn't
good enough.

Now - can anyone point me to a supplies for industrial strength glues that I can use. I understand
that I will need a slow cure epoxy type but this is as much as I've been able to find.

Recommendations on types and strengths would be appreciated.

Thanks in advance

Everso

Without knowing the parent materials being joined, i'd hesitate any recommendations. If i had to chose one... it'd be System Three's T-88 structural epoxy. A white sheet is available at there web site. I think Aircraft Spruce and Wicks carrys it among others. A lot of expermintal aircraft builders use it.... as do I.

PaPa <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Without knowing the parent materials being joined, i'd hesitate any recommendations. If i had to
chose one... it'd be System Three's T-88 structural epoxy. A white sheet is available at there web
site. I think Aircraft Spruce and Wicks carrys it among others. A lot of expermintal aircraft
builders use it.... as do I.

I know of a Tour Easy clone that was built entirely from scrap bikes and JB Weld. It recently was
sidelined by a structural failure- after 13 years of use. YMMV.

Jeff

Thank you both for your replies.

I have been looking at J B weld and it did seem to be well loved buy all who used it so it was
certainly on my list. I will however look up the T88 and see if I can do a comparison of them.

Thank you.

Everso

Quoted message said:

Hi all,

I've been researching recumbent for a while now and have decided that the only way I am going to
get bunt is to mae something myself. I currently do a 13 mile each way commute on a mountain bike
with all the pain that implies. After looking about I decided a trike was the way to go.

I will be using 3 children's mountain bikes for most parts. My local second hand shop will sell me
2 for £25 the pair so that's a good way there. I have a scaffolding pole (I know - heavy) that I
will be using a length of for the boom. I plan to attach a rear triangle from one of the bikes into
a suitably cut/shaped recess and mount the two front forks, via arms in a "conventional" cruciform
arrangement. This will allow me to use ordinary front wheels.

There are many compromises in there (to keep the price down) such as weight (I'd rather be heavy
than un-reliable) and the same size back wheel will cause a less comfortable ride than a larger
one but there you go. The idea is to see if I can get something that works and improve if it isn't
good enough.

Now - can anyone point me to a supplies for industrial strength glues that I can use. I understand
that I will need a slow cure epoxy type but this is as much as I've been able to find.

Recommendations on types and strengths would be appreciated.

Thanks in advance

Everso

I'd also hesitate to recommend without knowing more about the parent materials and the joint design.
A few pieces of general advice, however, many of the structural epoxies have very poor toughness and
impact loads on the joints could lead to them failing. I have the dubious pleasure of working with
several adhesive like that at work. They're good to over 7000 psi but tend to shatter when impacted.

Your surface preparation will have as much or more effect then the joint design and adhesive you
choose. I've also had to test what happens when you don't get the surface clean. Cleaning with a
good industrial solvent (preferrably not something toxic enough to make you regret it) together with
some surface roughening should be okay.

As I am a engineer dealing with these adhesives at work, I'm pre-disposed, but one thing I'd do is
get on some website like Loctite's industrial products and find a few adhesives that match what you
want to deal with (check the MSDSs to make sure you want to be using them at home) and do a general
search on the web for those. I've found a lot of small industrial supply houses sell some of the
better adhesives in small quantities.

Thanks for all the advice/watch outs/comments.

I think it's going to be JB weld. T88 looks good and I like the idea of an epoxy that dries to form
a slightly flexible joint but it's setting time of up to 24 hours is a bit long. I'm thinking that
if I carry JB weld in my kit it's 20 minute cure time leaves me the option of making repairs on the
road. This will mainly be a commuting to work machine and a joint could be fixed and left for the
work day till time to drive home (slowly).

I definitely take your point about joint preparation and do expect to spent a long time on it. The
first joint will be a length of scaffold pipe suitably shaped to take the bottom bracket of one of
the donor bikes. I'm also thinking of some sort of re-enforcing there as well. Maybe some heavy
gauge sheet metal shaped go from the pipe and onto the bottom of the frame - what do you
think/recomend.

Impact resistance was also something I am worried about as this can/will lead to sudden failure of
the frame - probably when I'm late for work and miles away from home. Is there anything I can do to
help make the joint more impact proof? Maybe build it up with several layers of fiber glass after
the joint has been made?

Once again thank you everyone for you time and comments.

Everso

[email hidden] wrote in :"]news:[email hidden]:

Quoted message said:

Impact resistance was also something I am worried about as this can/will lead to sudden failure of
the frame - probably when I'm late for work and miles away from home. Is there anything I can do
to help make the joint more impact proof? Maybe build it up with several layers of fiber glass
after the joint has been made?

Once again thank you everyone for you time and comments.

Everso

Please have a look at my experimental trike and hopefully you will learn from my mistakes
pictures.care2.com767377690Open ↗

The mistake usually made when using epoxy is just using a big gob of the stuff and expecting it to
hold up. Best is as a "gap filler", as much as possible like a lugged frame bike; wherein, instead
of brazing, epoxy is used.

The metal used was way too thick, and the weakest designed joint was where the rear wheel section
connects to the main tube. I used Aeropoxy, and the only joint where it gave loose was the joint
just mentioned. Otherwise a nifty machine, which has since been cannabilized for the components,
etc. The epoxy isn't real good for "sheer forces".

Happy trails, rorschandt

rorschandt said:

[email hidden] wrote in :"]news:[email hidden]:

Quoted message said:

Impact resistance was also something I am worried about as this can/will lead to sudden failure
of the frame - probably when I'm late for work and miles away from home. Is there anything I can
do to help make the joint more impact proof? Maybe build it up with several layers of fiber glass
after the joint has been made?

Once again thank you everyone for you time and comments.

Everso

Which set of pictures there please? I've had a look and can't see which joint you are talking about.

It sounds like I will have to re-enforce the joints where there is any sheer forces, something I was
seriously considering anyway.

Everso

Quoted message said:

Please have a look at my experimental trike and hopefully you will learn from my mistakes
pictures.care2.com767377690Open ↗

The mistake usually made when using epoxy is just using a big gob of the stuff and expecting it to
hold up. Best is as a "gap filler", as much as possible like a lugged frame bike; wherein, instead
of brazing, epoxy is used.

The metal used was way too thick, and the weakest designed joint was where the rear wheel section
connects to the main tube. I used Aeropoxy, and the only joint where it gave loose was the joint
just mentioned. Otherwise a nifty machine, which has since been cannabilized for the components,
etc. The epoxy isn't real good for "sheer forces".

Happy trails, rorschandt

rorschandt said:

... The epoxy isn't real good for "sheer forces".

What are "sheer forces"?

Tom Sherman - Quad Cities USA (Illinois side)

[email hidden] wrote in :"]news:[email hidden]:

Quoted message said:

rorschandt said:

[email hidden] wrote in :"]news:[email hidden]:

Quoted message said:

Impact resistance was also something I am worried about as this can/will lead to sudden failure
of the frame - probably when I'm late for work and miles away from home. Is there anything I can
do to help make the joint more impact proof? Maybe build it up with several layers of fiber
glass after the joint has been made?

Once again thank you everyone for you time and comments.

Everso

Which set of pictures there please? I've had a look and can't see which joint you are
talking about.

Specifically pictures.care2.com863844227Open ↗ The point where the rear stays connect was a
"sheer" joint, and in the end the only thing holding it was the stainless steel bolts. I COULD have
adapted it to rear suspension...(^:

mmm - not looking good for my application. It;s going to need a re-enforcing bat there. Who knows,
maybe even with u clamps.

Everso

rorschandt said:

[email hidden] wrote in :"]news:[email hidden]:

Quoted message said:

rorschandt said:

[email hidden] wrote in :"]news:[email hidden]:

> Impact resistance was also something I am worried about as this can/will lead to sudden failure
> of the frame - probably when I'm late for work and miles away from home. Is there anything I
> can do to help make the joint more impact proof? Maybe build it up with several layers of fiber
> glass after the joint has been made?
>
> Once again thank you everyone for you time and comments.
>
> Everso
>

Which set of pictures there please? I've had a look and can't see which joint you are
talking about.

Specifically pictures.care2.com863844227Open ↗ The point where the rear stays connect was
a "sheer" joint, and in the end the only thing holding it was the stainless steel bolts. I COULD
have adapted it to rear suspension...(^:

One caution about buying epoxy resin: It has a limited shelf life. After 6 months to one year,
depending on its type and storage temperature, it will deteriorate. After one to two years, it may
not harden at all. Even if older resin does harden, this doesn't indicate that the finished product
will be as strong or last as long as that made from fresher resin. Very hot or freezing temperatures
will hasten its decline. Understand that what I've said applies to liquid resin, not to that which
has been catalyzed and hardened. Good epoxy products can last for decades, if they aren't smashed up
or left out in the sunlight for long periods.

Buying from a local store that has only a small and seldom sold supply of epoxy, is the most
likely way to get an old and useless batch of it. Buy from an industrial supply dealer that
sells a lot of it to professionals. Such a business should be able and willing to tell you the
exact date it was manufactured and assure you that if any quality problems exist, that it would
be replaced or a refund given.

There are numerous types of epoxy resin and each region of the world has its own brands. A
professional supplier could advise you of the best variety for your purposes. In the U.S., the
W.E.S.T. system of epoxy, distributed by the Gougeon Bros., is well-regarded for penetrating
and coating wood. Other types are better suited for bonding other materials and for use with
fiberglass reinforcing cloth. Still others are formulated for thin surface coatings, in
varnish-like applications. I used a lot of D.D. Lak, from Denmark, in past years, as an epoxy
coating for wood-veneer boats. With a year each of college Swedish and Norwegian, I could
translate the instructions. My impression is that the quality of such products from England and
Scandinavia is better than those from the U.S. and the distributors there take more care with
their quality control in shipping and storage. I've bought thin marine plywood from England,
that was made with glue so good, that the layers couldn't be separated, even after an hour in a
pressure cooker.

Steve McDonald

they are forces encountered when the assembler is distracted by a set of pantyhose walking by. Shear
forces are those when the joint is loaded parallel to the bondline as opposed to tensile forces
which are perpendicular.

Tom Sherman <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

rorschandt said:

... The epoxy isn't real good for "sheer forces".

What are "sheer forces"?

Tom Sherman - Quad Cities USA (Illinois side)

Tom Sherman <[email hidden]> nitpicked in :"]news:[email hidden]:

Quoted message said:

rorschandt said:

... The epoxy isn't real good for "sheer forces".

What are "sheer forces"?

Tom Sherman - Quad Cities USA (Illinois side)

Can't I be human for even a moment? SHEAR, then.

[email hidden] (Jim Plaia) wrote in :"]news:[email hidden]:

Quoted message said:

they are forces encountered when the assembler is distracted by a set of pantyhose walking by.

Actually pantyhose don't do it for me. Now those sheer see-thru panties are um, uh uuhhh... Q^:

Quoted message said:

Shear forces are those when the joint is loaded parallel to the bondline as opposed to tensile
forces which are perpendicular.

correct.