Our new dinghy, a Highfield 360CL, has had a few issues.  Most recently the velcro holding the dinghy chaps (which are the cover to protect the pontoons) stopped sticking to the dinghy.  

We had our dinghy chaps custom made by Kim at Masterpieces in Canvas about 8 months ago.  She did an amazing job and we have had over a dozen people compliment us on the well made covers!   It was not her fault that the velcro sticky back stopped sticking.

The Problem

Kim used the sticky glue on the back of the velcro to adhere the chaps to the dinghy. The male part of the velcro stuck to the chaps and the female part (soft) of the velcro stuck to the dinghy.  In theory this works and it did for a short while (8 months).  But as the dinghy gets hot and cold in the sun it expands and contracts.  This causes the glue on the velcro to loosen and come off.  So, not a good long term plan.

With our last dinghy, we had the velcro glued onto hypalon strips, then sewn together, then we used special glue to stick the hypalon strips to the hypalon dinghy.  We should have remembered to do that to these chaps, but it slipped our mind as we had so much other stuff going on.  Our new dinghy is made from PVC not hypalon unfortunately. 

Hindsight is 20-20 they say.

The Remedy

We had a lovely conversation with Tim at Northland Inflatables.  He was able to sell us PVC strips and special PVC contact glue.  In addition, he walked us through the best way to remove the glue from the dinghy, the application of the velcro to the PVC, and the glueing process of the PVC strips to the dinghy. He is a wealth of information!

Tim informed us that the PVC strips will be stronger if you cut them diagonally across the fabric (rather than with the grain of the fabric).  Good tip.

We were ready to start this project after purchasing our special 2-part PVC contact glue, special brush, and 18m of 30mm wide PVC strips!

Step 1A: The Prep

It seems like all I do is glue removal projects!   Removal of all of the graphic stickers and its 23 year old glue, scraping all of the glue, 5200 and silicone from the ceiling panels, 6 hatch frames and of their adhesive, and now the dinghy glue.  And the funny thing is that they are all different, using different glues, on different surfaces, and requiring different removal techniques.

We removed the outboard and hauled the 75kilo dinghy up using our spin halyard.  Placing the dinghy on our two bean bags allowed easier access to the glue areas on the outside (see photo below).

The dinghy has 23 pieces of velcro spanning over 18 meters.  Tim had suggested we make the strips 30mm wide even though our velcro was only 25mm. He thought it might make sewing easier.  But in retrospect we should have just got 25mm strips.  Now we have to accomodate for the extra 5mm.  What I decided to do was apply the velcro on the bottom of each strip and had the extra 5mm on the top.  The reason I did this was because several velcro strips aligned with a seam and we did not want the white PVC strips to show.

We created a sheet and labeled/numbered each piece of velcro so we know exactly where it goes when we put it back.

Step 1B: More Prep

We used a pencil to mark where each piece of velcro (the edges, start and end) and then we taped all around the velcro before removal.  Taping will help limit the spread of glue and MEK when you start the adhesive removal process.  

We were really good about marking the edges but we did not tape until afterwards.  So the problem was the MEK took off the pencil markings so we had to guess where some of the pieces went. And some of the MEK extended beyond the velcro area causing a very slight discoloration.  So, tape before removing your velcro.

Step 2: The Removal

I carefully remove each of the 23 strips of velcro, one at a time. I place them on the PVC strips lining them up on the edge and labeling each one so I know where they go when we have to put them back onto the dinghy.

Next I get to removing the tons of glue off the dinghy.

We cannot use anything sharp to remove the glue because we would risk puncturing the pontoon (very bad).  I tried a rubber square, a plastic paddle, and a cool tool Aaron from Norsand Boatyard had given me and none of them worked.

Finally Matt brought out a putty knife that he adapted for me.  He rounded the corners and dulled the blade.  Eventually, I was able to remove the adhesive while using a heat gun to warm up the glue and the modified putty knife.  This would get the large globs off.  Then I went back with MEK (really nasty stuff) and a non-absorbent rag to remove the difficult to see remnants of the glue.  If you use an absorbent rag you end up wasting a lot more MEK. But you have to wear very thick, high quality gloves as the MEK will eat your skin and nails!

After many hours we finally have a dinghy without residue…clean.  It is always amusing to me that I have such a hard time removing adhesives.  Why do you ask?  Well, I am removing it because it no longer sticks, so why is it hard to come off?  Why I ask you?

Note

Tim from Northland Inflatables told us to put the velcro on the dull side of the PVC strips.  The dull side is the side that has UV protection which does not stick as well as the clean shiny side with no UV protection. The trick is trying to determine the shiny side from the dull side while in the sun.  So, we stick the velcro to the dull side, then sew it on.  This leaves the shiny, clean side ready for the contact glue to stick to the dinghy.

Step 3: Sewing

I tried to use our trusty Baby Lock sewing machine to sew the velcro to the PVC strips.  However, the machine struggled with the PVC as it was slippery and wouldn’t move with the machine’s foot.  And it made the stitching on the back look funny.

Matt breaks out our new “to us” Sailrite Sewing machine.  I had not used this machine yet as it totally intimidated me!  But, you got to start somewhere.  The Sailrite has much better feet and it just sucked the strips right through!

I had 38 meters of sewing to do as I sewed all four sides of each of the 23 strips of velcro to the PVC – it will not move now!

Step 4: Glue PVC strips to Dinghy

We did a lot of research on what was the best glue to stick things to PVC and either Bostik 995 or PVC contact glue were stated to be the best.  We found a tiny bottle (50ml) of Bostik 995 at All Marine for over $100.  Well that won’t do as we need over 300ml.  So, we asked Tim what we should use and suggested this special contact PVC glue that he uses on all of his dinghy repairs.  He sold us 300ml for $25.  Sweet as!

We run MEK along the strips and the dinghy to ensure there is nothing that will prohibit a good stick.

Next, we tape off the dinghy where each strip goes.  This will protect the dinghy from getting excess glue on it and it will help us align the strips in the exact place since we won’t have the luxury to move them around once they make contact with each other.

Matt and I work together to adhere the PVC strips.  Tim gave us a “chip” brush that he cut down to almost a stub and then rounded the corners.  He said this will help us to use less contact glue.

First you apply the contact glue to the PVC strip and then to the corresponding area on the dinghy.  You let it set for 10-15 minutes.  Then you go back with a heat gun to warm both up and slowly and carefully apply the PVC strip to the dinghy.  I say “slowly and carefully” because once the PVC strip makes contact with the dinghy it aint movin.  

Then I follow behind with a dowel to press the PVC strip to the dinghy and ensure it is stuck on good.

We ended up having to get an additional canister of the special PVC contact glue to finish our project.  But we did use it for two other smaller projects.  In the end I think we probably used 350-400ml.  We were probably more generous with the glue than necessary.

Completion

As you can see we are doing our best to leave no room for errors and to ensure this is stuck on good.  After a week of work we are finally done and our beautiful chaps are now snug as a bug in a rug!  Let’s hope these last us many years.

Our blog posts run 10-12 weeks behind actual live events.  This blog post occured in early January 2024.  Don’t miss out on our luxurious experience at Wai Ariki Hotsprings and Spa – check out our last blog post.