Subject: Re: fixing formica

From: [email-masked] (Harvey Freeman)
Date: 10 Feb 1997 00:15:12 GMT

John Paquay ([email-masked]) wrote:
: In article <[email-masked]>, [email-masked] says...
: >
: >
: >
: >Better and/or faster is good. Come to think of it, I wonder whether a hot iron 
: >over the delaminated section would work on old contact cement. I know it works 
: >for new cement, but haven't tried it with old cement. That would be easiest of 
: >all, if it works.
: >

: Provided that the surfaces haven't been fouled by dirt, grease, etc.,
: this method usually does work, and it's a whole lot easier than tearing
: up a section of laminate big enough to work new cement into.  But if
: the iron doesn't work, your best solution would be to inject some
: Titebond II into the lifted area and clamp it down tight overnight... that's
: assuming, of course, that the lifting area is near an edge.

: Note that the hot iron method will melt the adhesive, but you should
: apply pressure to the area while it cools to make sure it the adhesive
: sets again as it should.  A cool, damp rag or towel works well for this,
: and speeds the cooling.

: -- 
: John Paquay
: [email-masked],  [email-masked]
: http://www.physics.purdue.edu/~jep/
: -----------------------
: I know you believe you understand what you think I meant.
: But I'm not sure you realize that what you thought you heard
: is not what I said...

Harvey Freeman wrote on Sunday Feb. 8, 1997  [email-masked]

The original post does not say if the delaminated area is at an edge.  If 
it is in the middle of the sheet then none of the above work except maybe 
the iron if you do not over heat and blister the laminate.  A carpenter 
told me that he would drill a hole into the air bubble from the bottom 
without drilling into the plastic laminate.  This is easy with a precise 
depth gauge on the drill.  Use one of the spray contact cements which 
comes with a thin plastic tube addition for the nozzle to put cement into 
the air bubble.  Wait the required time and weight down the spot until cured.

Personally, I only had new work delaminate once and that was my first job 
because I read the directions and followed them too closely.  Now I put 
TWO coats of cement on the base material and one on the plastic 
laminate.  The first coat is actually a sealer because too much soaks 
into the material.

--
----------------------------------------------------------------------------
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123 School Ave.        !    1-902-445-2832 (R)
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Canada, B3N 2E1        !    1-902-423-3063 (F)
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Precision 50 Table Saw Fence Page www.chebucto.ns.ca/~ac258/Precision_50.html
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From: [email-masked] (StkyFingr)
Date: 10 Feb 1997 04:59:52 GMT

<<I wonder whether a hot iron 
over the delaminated section would work on old contact cement. I know it
works 
for new cement, but haven't tried it with old cement.>>

No.  If it were a top that was recently made, then a hot iron might work. 
If the top is over a couple of months old, then forget it.  Contact loses
the ability to be reactivated with heat as it ages.  Plus the top most
likely came up because of lack of adhesive in the first place.  It would
be best to re-coat and repair.

Sticky Fingers

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From: [email-masked] (StkyFingr)
Date: 10 Feb 1997 04:57:02 GMT

<<Most kinds of contact glue should not be 
frozen, so don't leave it out in your garage.>>

Solvent based contact cements will not freeze.  They may phase if they
reach and extremely low temperature, but when they are warmed back up to
65 degrees F or higher and agitated, they will go back into solution and
be as good as new.

Water based contact cements are not freeze/thaw stable and will ruin if
frozen.

Sticky Fingers

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From: [email-masked] (StkyFingr)
Date: 10 Feb 1997 05:04:46 GMT

<<Note that the hot iron method will melt the adhesive, but you should
apply pressure to the area while it cools to make sure it the adhesive
sets again as it should.  A cool, damp rag or towel works well for this,
and speeds the cooling.>>

Heat causes contacts to soften and allow re-bonding.  Depends on the type
of contact used as to the amount of heat needed.  However, the heat will
not cause contact cement to melt.  Using heat to bond a delaminated piece
of HPL will only work if the top is fairly new, assuming there was enough
adhesive applied in the first place.  Contacts loose the ability to be
reactivated by heat as they age.

Sticky Fingers

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From: [email-masked] (Trevor Galvin)
Date: Tue, 11 Feb 1997 08:59:07 GMT

If you have a problem with delamination and you want to fix it right I
would use a little lacquer thinner in the problem area to expose
enough of it to do the necessary clean up of any foreign material and
give myself some room to work. Keep a wedge in place to let air in and
dry off. When dry use contact cement on both surfaces allowing time to
dry. Apply a second coat also allowing time to dry. Press the pieces
back together, use a scrap of 2x4 and a hammer to ensure you have good
contact.. Like someone alrady mentioned you needs two coats for best
results.

Trevor

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From: [email-masked] (StkyFingr)
Date: 12 Feb 1997 00:17:59 GMT

<<If you have a problem with delamination and you want to fix it right I
would use a little lacquer thinner in the problem area to expose
enough of it to do the necessary clean up of any foreign material and
give myself some room to work.>>

That is not good.  Do not ever use lacquer thinner to delaminate or flush
out spray equipment.  Lacquer thinner can leave an oily film which will
inhibit the new application of contact adhesive, and could lead to
delamination.  Use an approved solvent for any delaminating or flushing of
equipment.  You can use toluene if you want to use a flammable solvent or
1,1,1 trichloroethane (if you can still find it) or methylene chloride if
you want to use a N/F solvent.  These solvents are the main solvents used
in flammable and N/F contact adhesives to dissolve the neoprene into
solution.

If you do delaminate with solvent, you will want to give the material
several hours for the solvent to breath back out of the plywood or
particle board core.  Otherwise you will get solvent entrapment which will
lead to bubbling and/or edgelift.

<<Press the pieces back together, use a scrap of 2x4 and a hammer to
ensure you have good contact..>>

The correct method for pressure is a 3" J-roller.  A mallet by itself or
with a block is insufficient.  You must apply 25 lbs per sq. in. for
proper pressure.  The pressure applied by the head of the mallet spreads
out over the surface area of that mallet, plus you are not getting uniform
pressure in the surrounding area.  When a block is used with that mallet,
you are spreading out the pressure even further, resulting in lack of
pressure.  Let's say you use a block that is 4"X4" and hit it with a
mallet at 100 lbs. of pressure.  There are 16 sq. in. for that 100 lbs to
be dispersed, which means if it dispersed evenly, you would get 6.25
lbs/sq. in. of pressure.  This is inadequate.  However, the pressure is
not going to disperse evenly, you will get more in the middle of the block
where the mallet head hit and less pressure as it travels out to the edge
of the block.  USE A 3" J-ROLLER FOR PRESSURE.  The pressure is spread
along the very edge of the roller in contact with the surface, meaning you
press down with 75 lbs to achieve 25 lbs/sq. in.

<<Like someone alrady mentioned you needs two coats for best results.>>

Not necessarily.  If after applying the first coating of adhesive and
allowing it to dry, and when it is ready to index together, the adhesive
surface on both the HPL and the core is shiney, then you have applied
enough adhesive.  If however you have some dull areas, then you did not
apply enough adhesive, had soak in, or a combination of both.  Dull areas
would have to be re-applied and allowed to dry.  Double coating is usually
done on very porous substrates such as plywood, or on the edges of the
core.  The first coat acts as a sealer, preventing soak in of the second
coating.

Sticky Fingers

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From: [email-masked] (StkyFingr)
Date: 12 Feb 1997 15:42:38 GMT

Sticky Fingers