Filling Screw Holes

Disclaimer:  I’m brand new to welding plastic.  Please consider this post a “What I did” rather than a “How to”.  If you see any glaring mistakes, please point them out!
 

I wanted to move my anchor line Cam Cleat to a better location but what to do with the holes I’d drilled?  Luckily I read a couple of posts on this site about welding plastic, so now I’m an expert. 



First off, I removed the Cam Cleat and cleaned the area around the holes with acetone.



Next, I roughed up the inside diameter of and area immediately surrounding the hole to improve the bonding of the patch to the hull and to ensure that any residual GOOP was removed.



For filler, I used material I’d removed during a hatch installation.  To melt the filler, I used an old Weller 25 Watt soldering iron.  This iron worked out really well in this application.  It gets hot enough to readily melt this type of plastic but it’s cool enough that you get a long working life before the plastic burns.



I practiced filling holes on the extra material I had and found that this type of plastic retains heat for a long time.  This is very useful because it allows you to keep the entire circumference of a small hole molten while you feed filler material into the hole.  It also means that a gob of that plastic will continue to cook your thumb long after it’s removed from the soldering iron (ask me how I know  ).



It took a couple of tries to get the hole filled completely.  I judged my success by snaking my hand thru a hatch, feeling for material coming thru the back of the hole.  With the hole filled, I worked the soldering iron around the outside of the hole to ensure that the plug was supported by more than just the inside diameter of the hole.



After letting the plugs cool completely, I used a metal rasp to remove most of the extra material.



Next, I feathered the edges of the weld using a coarse sandpaper on a sanding block followed by a medium fine wet emery cloth.  The emery cloth also removed most of the deep grooves from the rasp and coarse sandpaper.



Left = Emery Cloth                                                 Right = Coarse Sandpaper

I left a little raised area around the hole for extra strength.  This might not have been necessary but it’s a habit I developed from years of surfboard ding repair.

To finish it off, I used a little car polish and a buffer to smooth out the fine scratches from the emery cloth.



And Voila!

That is awesome !!!!    I think I can even fill holes now!!! 

In the past, I've just put a short bolt/nut back in the holes ... gooped of course.   It don't look bad at all.

-Allen