What is the best product to adhere EPDM to a preformed pond? Please be specific.

solvent based cements / adhesives do little to adhere sufficiently to
PE or PP type plastics........

Short of welding with a hot air welder, it is best to scrap a layer
or so of the original surface off with a scraper (get rid of any
surface oxidation) pass a neutral flame (from hand held propane
torch) along and around the surface you intend to bond to, scuff wioth
sandpaper....then apply your adhesive of choice.......believe it or
not, these plastics oxidize fairly rapid in normal atmosphere
environments, and can oxidize within hours even as a new item right
out of the mold.......so ts important to remove oxidation before
glueing it up. Also by passing a flame over a preforms surface prior
to bonding, it changes the surface of the materials molecular
structure which aids in making a good bond.


I have found a special adhesive that is made specifically for plastics
typically found in preformed products.........but its really pricey,
and you have to buy a factory kit of the stuff which consists of 12
packets of adhesive. Until you buy this adhesive and considering the
small quanity in each packet, it would be cheaper to replace the
liner. Its big time $$$

The standard 3M 4200/5200 adhesives do not hold sufficiently without
further use of mechanical fasteners, but they will make a suitable
joint when used with fasteners.

Scotch-Weld DP-190, which is expensive. The 1.7 OZ packets are only
about $14 each, but these packets also require a proper applicator tip
for each use.......and minimum package of this adhesive is 12 packets,
so it is kind of pricey, but it works.........

Lord Corporation's 7540-AB urethane adhesive will also work, but it to
is pretty pricey and may be a bit harder to find. It is packed in 50
ml packets and costs perhaps $10 per packet, but once again minimum
package is 12 packets..........

There is a product made that will allow you to stick teflon to teflon
and its reported to work with PP or PE and most all other hard to
stick materials.......but I don;t know if it would be suitable for use
with fish or not. It smells like mothballs for about a month after its
applied, and carries a hazmat charge. and comes in 1 qt. containers
at $109 a qt...........This stuff etches the surfaces, to the point
that most any adhesive will stick, such as regular old contact
cements.

I think your best solution to adhering a liner to a preform would be
to use regular old RTV silicone product, in conjunction with a strip
of like preform material to make a scab patch and use mechanical
fasteners to prevent any possible lifting or shear of the applied
joint. Sandwhich the liner between the preform and the scab patch with
RTV between each and every piece after de-oxidizing the surfaces
(scraping, flame treatment and sandpaper)do not use any chemical type
cleaners after deoxidizing, apply RTV and clamp up and then install
some stainless steel fasteners with flat washers or finishing washers
to secure it. Coat the fasteners threads with RTV as well. YOu should
wind up with a good strong water proof connection that will not lift
or peel or shear and make a leak.
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Hi Roy, you seem to be the man with the know how!
Here is a link to a picture of what I am trying to accomplish.
http://funjax.com/pondhole
My plan is to cut a hole in the other pond and to glue EPDM to the inside of
each pond.
The hole at the lip is about 10" across.
Please take a look at picture and tell me how you would proceed.
Thanks for your help!, Larry



"Roy" wrote in message
...
solvent based cements / adhesives do little to adhere sufficiently to
PE or PP type plastics........

Short of welding with a hot air welder, it is best to scrap a layer
or so of the original surface off with a scraper (get rid of any
surface oxidation) pass a neutral flame (from hand held propane
torch) along and around the surface you intend to bond to, scuff wioth
sandpaper....then apply your adhesive of choice.......believe it or
not, these plastics oxidize fairly rapid in normal atmosphere
environments, and can oxidize within hours even as a new item right
out of the mold.......so ts important to remove oxidation before
glueing it up. Also by passing a flame over a preforms surface prior
to bonding, it changes the surface of the materials molecular
structure which aids in making a good bond.


I have found a special adhesive that is made specifically for plastics
typically found in preformed products.........but its really pricey,
and you have to buy a factory kit of the stuff which consists of 12
packets of adhesive. Until you buy this adhesive and considering the
small quanity in each packet, it would be cheaper to replace the
liner. Its big time $$$

The standard 3M 4200/5200 adhesives do not hold sufficiently without
further use of mechanical fasteners, but they will make a suitable
joint when used with fasteners.

Scotch-Weld DP-190, which is expensive. The 1.7 OZ packets are only
about $14 each, but these packets also require a proper applicator tip
for each use.......and minimum package of this adhesive is 12 packets,
so it is kind of pricey, but it works.........

Lord Corporation's 7540-AB urethane adhesive will also work, but it to
is pretty pricey and may be a bit harder to find. It is packed in 50
ml packets and costs perhaps $10 per packet, but once again minimum
package is 12 packets..........

There is a product made that will allow you to stick teflon to teflon
and its reported to work with PP or PE and most all other hard to
stick materials.......but I don;t know if it would be suitable for use
with fish or not. It smells like mothballs for about a month after its
applied, and carries a hazmat charge. and comes in 1 qt. containers
at $109 a qt...........This stuff etches the surfaces, to the point
that most any adhesive will stick, such as regular old contact
cements.

I think your best solution to adhering a liner to a preform would be
to use regular old RTV silicone product, in conjunction with a strip
of like preform material to make a scab patch and use mechanical
fasteners to prevent any possible lifting or shear of the applied
joint. Sandwhich the liner between the preform and the scab patch with
RTV between each and every piece after de-oxidizing the surfaces
(scraping, flame treatment and sandpaper)do not use any chemical type
cleaners after deoxidizing, apply RTV and clamp up and then install
some stainless steel fasteners with flat washers or finishing washers
to secure it. Coat the fasteners threads with RTV as well. YOu should
wind up with a good strong water proof connection that will not lift
or peel or shear and make a leak.
Visit my website: http://www.frugalmachinist.com
Opinions expressed are those of my wife,
I had no input whatsoever.
Remove "nospam" from email addy.

Are you simnply joining the two preforms with a piece of EDPM liner
material? I assume they are both set at orclose to the same level.

If I was going to join two preforms as such I wuld look and find a
piece of old preform or a piece of polyethyene plastic and cut it into
a strip approx 1inch wide. You will need enough strip material to
start at the top of one side down and around and up the other side of
each preform. I don;t know how hard EDPM liner material is to stretch
or form but fit every thing up dry first. Use a couple of small stove
bolts of #8 or 10 diam to hold all in place while you get the holes
drilled. Layt in the liner, afainst the preforms interior, and lay one
of the precut 1" wide strips over it, drill a hole though strip, liner
and preform, and secure with fastener (temporary). Continue working
down and across and up the other side drilling a hole and stretching
and fitting the strup and liner into place, and secure with more temp
fasteners. Its gonna get old fast installing and removing these
fasteners but its the only way your going to keep things aligned..
Unless you know someone who works sheetmetal or aircraft, you may be
able to borrow some Kleco's to use instead of having to install and
remove the fasteners, as it will go much quicker with Klecos.......so
if you have gotten along this far in life without em and don;t know
what they are, they certainly are not cost effective to buy just for
this project, as they run about $4.00 each plus about $30 for the tool
to use them............and your gonna need quite a few.

Depending on how tight and snug you can get the strip and liner
material to lay in the preforms cutout, will determine how many
fasteners you maya need to install overall. Once one preform section
is done, do the same to the other........I would suspectr its gonna be
hard and you will have some bulges or wavey sections but its
doable.....Just guessing I would suspect your gonna need a fastener at
least every inch or so just to pull things tight and hold things in
place.

Once both sides are fit and drilled with the strip and liner, remove
all fasteners. Make sure you mark eachpiece for proper orientation for
reassembly. Clan both sides of the liner well, and clean and scuff up
surface of preform and strip that contacts the liner. Apply a liberal
bead of RTV of thickness sufficient width or make two beads in the
area the liner is going to lay on, under the strip, and on the
preform, you can also smear a thickness of RTV on both sides of liner,
and then start to install the permanent fasteners your going to use.
Snug everything down, and sort of fillet what RTV oozes out between
the liner / stip and preform with a damp finger.
Make sure RTV oozes out from the entire length of the strip and
liner .

I would use stainless steel flat head #8 machine screws, with a #8
stainless steel finishing washer under the head of the flat head
machine screw. Use a stainless flat #8 washer on the back side
(towards dirt) and secure with a stainless nut. You can get all these
types of stainless fasteners at Home Depot or a marina.......
Let it all setup at least a full 24 hours before filling with water.

I would suspect if its done properly it will hold water and should
work fine. It should last along time, if the soil and ponds are not
disturbed to put additional stress on the pieced in section.

Hope this helps. Its the way I would do it if I was doing such a
project.

Regards

Visit my website: http://www.frugalmachinist.com
Opinions expressed are those of my wife,
I had no input whatsoever.
Remove "nospam" from email addy.

thanks Roy!!!!

"Roy" wrote in message
...
Are you simnply joining the two preforms with a piece of EDPM liner
material? I assume they are both set at orclose to the same level.

If I was going to join two preforms as such I wuld look and find a
piece of old preform or a piece of polyethyene plastic and cut it into
a strip approx 1inch wide. You will need enough strip material to
start at the top of one side down and around and up the other side of
each preform. I don;t know how hard EDPM liner material is to stretch
or form but fit every thing up dry first. Use a couple of small stove
bolts of #8 or 10 diam to hold all in place while you get the holes
drilled. Layt in the liner, afainst the preforms interior, and lay one
of the precut 1" wide strips over it, drill a hole though strip, liner
and preform, and secure with fastener (temporary). Continue working
down and across and up the other side drilling a hole and stretching
and fitting the strup and liner into place, and secure with more temp
fasteners. Its gonna get old fast installing and removing these
fasteners but its the only way your going to keep things aligned..
Unless you know someone who works sheetmetal or aircraft, you may be
able to borrow some Kleco's to use instead of having to install and
remove the fasteners, as it will go much quicker with Klecos.......so
if you have gotten along this far in life without em and don;t know
what they are, they certainly are not cost effective to buy just for
this project, as they run about $4.00 each plus about $30 for the tool
to use them............and your gonna need quite a few.

Depending on how tight and snug you can get the strip and liner
material to lay in the preforms cutout, will determine how many
fasteners you maya need to install overall. Once one preform section
is done, do the same to the other........I would suspectr its gonna be
hard and you will have some bulges or wavey sections but its
doable.....Just guessing I would suspect your gonna need a fastener at
least every inch or so just to pull things tight and hold things in
place.

Once both sides are fit and drilled with the strip and liner, remove
all fasteners. Make sure you mark eachpiece for proper orientation for
reassembly. Clan both sides of the liner well, and clean and scuff up
surface of preform and strip that contacts the liner. Apply a liberal
bead of RTV of thickness sufficient width or make two beads in the
area the liner is going to lay on, under the strip, and on the
preform, you can also smear a thickness of RTV on both sides of liner,
and then start to install the permanent fasteners your going to use.
Snug everything down, and sort of fillet what RTV oozes out between
the liner / stip and preform with a damp finger.
Make sure RTV oozes out from the entire length of the strip and
liner .

I would use stainless steel flat head #8 machine screws, with a #8
stainless steel finishing washer under the head of the flat head
machine screw. Use a stainless flat #8 washer on the back side
(towards dirt) and secure with a stainless nut. You can get all these
types of stainless fasteners at Home Depot or a marina.......
Let it all setup at least a full 24 hours before filling with water.

I would suspect if its done properly it will hold water and should
work fine. It should last along time, if the soil and ponds are not
disturbed to put additional stress on the pieced in section.

Hope this helps. Its the way I would do it if I was doing such a
project.

Regards

Visit my website: http://www.frugalmachinist.com
Opinions expressed are those of my wife,
I had no input whatsoever.
Remove "nospam" from email addy.