Scotchweld 1838

I was just reading the instructions for the LOC 3.90" V-2, and they recommend using Scotchweld 1838 epoxy on the boattail. I've never heard of this stuff before, but it's $60 for 2oz tubes! Is anybody familiar with it? Is there a comparable and less expensive product?

I have never used this particular product but have used several of the Scotchweld line of epoxies. I think that is one specifically made to bond plastic. I think you would be fine with your usual epoxy as long as you wash the boattail to remove any mold release and roughen the surface well before gluing.

I have bought the same V-2 kit. The Scotchweld 1838 has a tensile strength of 4200 psi. I could not find Scotchweld 1838 locally, so I used JB Weld, which has a tensile strength of 3960 psi. JB Weld was recommended for the Aero Pack Quick-Change 38mm Motor Retainer and it was 1/10th the cost. I cleaned the boat tail with 95% isopropyl alcohol, so we will see how well it works. What did you use and how did it work?

Not sure about that product ,but I have built several kits that use polypropylene plastic as boat tails (PML) and I just use a good quality 2 part 50/50 5 min. epoxy (although 15 -20-30 min. are all OK)

As mentioned ,the important thing is to wash the parts with dish soap before any sanding is done (don`t want to scrub the release agent into the plastic) then I sand with 80 grit sandpaper. I even use my Exacto knive and score cross hatches into the plastic to even further help the epoxy "key" into the cuts and scratches to make sure I`m getting a good mechanical bond.

Also ,I always wash the parts with Isopro.alcohol after sanding and before I apply epoxy.Now keep in mind ,with the PML kits I`ve made ,I`m joining Quantum tube to poly (both plastics made of polymers) and have never had any kind of seperation of parts flying with HP motors and even very hard landings (no chute deployment on my 3" Bullpup)

I trust with your kit ,the BT is cardboard ,so the bond would be even stronger ,as some of the epoxy will soak into the fibers.

That $ 60 bucks would be better spent on more kits and reloads :wink:

Take care


Paul T


Boy......that was rather long winded wasn`t it :blush: