Osmosis on topsides
 

Hi,

I viewed a 1983 Vancouver 32 recently that had osmotic blistering
covering about 4 feet of the topsides below the teak cap rail on both
port & starboard aft quarters. There are no blisters or signs of
osmosis below the waterline.

I'm concerned as to what might be causing these blisters, there are no
visual clues. The deck joins the hull underneath the cap rail and
maybe moisture has entered here?

Has anyone seen anything similar before?

Thanks,
Peter

Osmosis on topsides
 

Our boat has it and I was told that it was from being shrink wrapped
down to the waterline and the numb kid assigned to shrink it using too
much heat. It's on the quarters because that's how far he got before
someone ran up yelling, "You #$%^(*&^$ numbskull!" I could see traces
of the old shrink wrap edge and where it was cut back up to the rail
so I believe the story.

I was concerned about the ones on our boat; especially when I heard
the cost of repair. Someone told me to forget it, I would never see
them in the water, even at the dock. Sure enough, they are
practically invisible. I haven't noticed them once in two seasons and
forgot they were there until your post reminded me.

No blistering below the waterline or elsewhere on our boat either.
Sign of a good layup.

Forget about them and go sailing.

--

Roger Long



"PeterS" wrote in message
oups.com...
Hi,

I viewed a 1983 Vancouver 32 recently that had osmotic blistering
covering about 4 feet of the topsides below the teak cap rail on
both
port & starboard aft quarters. There are no blisters or signs of
osmosis below the waterline.

I'm concerned as to what might be causing these blisters, there are
no
visual clues. The deck joins the hull underneath the cap rail and
maybe moisture has entered here?

Has anyone seen anything similar before?

Thanks,
Peter

Osmosis on topsides
 

This was a fairly common occurance on some boats from the mid-70s
through mid 80s. Its not serious and can be easily 'patched'.
What happened is that the lay-up crew sprayed-on the gelcoat to the
mold, then went home allowing the gelcoat to fully cure, and gather
dirt, dust, etc. When they came back in the morining they simply
started where they left off with matting, roving, etc.

The lay-up of polyester needs to be a continuous process so that no one
section of the laminate cures before the next layer is applied. Most
of the 'high-end' builders now do the layup in one single process with
no interruptions until fully finished.

Was your V32 built by Tayana? My Tayana 37 has the same 'problem' ...
I simply 'opened' all the above the waterline teeny blisters and filled
with correctly matched gelcoat, etc. Inside those 'blisters' was a
talc-like substance .... probably dust from the floor sweepers after
the layup crew went home for the evening.




In article .com,
PeterS wrote:

Hi,

I viewed a 1983 Vancouver 32 recently that had osmotic blistering
covering about 4 feet of the topsides below the teak cap rail on both
port & starboard aft quarters. There are no blisters or signs of
osmosis below the waterline.

I'm concerned as to what might be causing these blisters, there are no
visual clues. The deck joins the hull underneath the cap rail and
maybe moisture has entered here?

Has anyone seen anything similar before?

Thanks,
Peter

Osmosis on topsides
 

Rich Hampel inscribed in red ink for all to know:
This was a fairly common occurance on some boats from the mid-70s
through mid 80s. Its not serious and can be easily 'patched'.
What happened is that the lay-up crew sprayed-on the gelcoat to the
mold, then went home allowing the gelcoat to fully cure, and gather
dirt, dust, etc. When they came back in the morining they simply
started where they left off with matting, roving, etc.

The lay-up of polyester needs to be a continuous process so that no one
section of the laminate cures before the next layer is applied. Most
of the 'high-end' builders now do the layup in one single process with
no interruptions until fully finished.

Was your V32 built by Tayana? My Tayana 37 has the same 'problem' ...
I simply 'opened' all the above the waterline teeny blisters and filled
with correctly matched gelcoat, etc. Inside those 'blisters' was a
talc-like substance .... probably dust from the floor sweepers after
the layup crew went home for the evening.




In article .com,
PeterS wrote:


Hi,

I viewed a 1983 Vancouver 32 recently that had osmotic blistering
covering about 4 feet of the topsides below the teak cap rail on both
port & starboard aft quarters. There are no blisters or signs of
osmosis below the waterline.

I'm concerned as to what might be causing these blisters, there are no
visual clues. The deck joins the hull underneath the cap rail and
maybe moisture has entered here?

Has anyone seen anything similar before?

Thanks,
Peter



I love it! CSI - Boat Builders!

Osmosis on topsides
 

Rich,

Many thanks for the reply, I feel more confident about it now I
understand how it might have occurred.

This V32 was made by Pheon Yachts in the UK.

Rich Hampel wrote:
This was a fairly common occurance on some boats from the mid-70s
through mid 80s. Its not serious and can be easily 'patched'.
What happened is that the lay-up crew sprayed-on the gelcoat to the
mold, then went home allowing the gelcoat to fully cure, and gather
dirt, dust, etc. When they came back in the morining they simply
started where they left off with matting, roving, etc.

The lay-up of polyester needs to be a continuous process so that no one
section of the laminate cures before the next layer is applied. Most
of the 'high-end' builders now do the layup in one single process with
no interruptions until fully finished.

Was your V32 built by Tayana? My Tayana 37 has the same 'problem' ...
I simply 'opened' all the above the waterline teeny blisters and filled
with correctly matched gelcoat, etc. Inside those 'blisters' was a
talc-like substance .... probably dust from the floor sweepers after
the layup crew went home for the evening.




In article .com,
PeterS wrote:

Hi,

I viewed a 1983 Vancouver 32 recently that had osmotic blistering
covering about 4 feet of the topsides below the teak cap rail on both
port & starboard aft quarters. There are no blisters or signs of
osmosis below the waterline.

I'm concerned as to what might be causing these blisters, there are no
visual clues. The deck joins the hull underneath the cap rail and
maybe moisture has entered here?

Has anyone seen anything similar before?

Thanks,
Peter