After much consideration I decided to attach my front sight with a metal epoxy such as JB weld. I searched the net and the general consensus is that it works for this application. If the front sight does get knocked of it will not impact the use of the gun as much since we are talking about a shot gun, not a rifle or pistol.
For those that have doubts, here are the properties of the JB Weld Part number 8265
Tensile Strength: 3960psi
Flex Strength: 7320psi
Tensile Lap Shear: 1040psi
Resistant to: 600° F
When you take into consideration that the bonded area is .825 square inches the risk of joint failure is very low. However, to add an extra measure of security and to aid in the alignment of the sight, I decided to drill a hole in the base of the sight that fit over the original sight bead on my Mossberg 500.
Here is how I performed that process:
- From the top, use a 11/64" bit to spot drill the bottom of the adjustment cup. This area is milled flat and spot drilling it centers the next bit perfectly.
- From the top, drill though the entire sight with a 3/32" bit
- From the bottom, drill through the base of the sight with a 1/8" bit
- From the bottom, use a 3/16" bit to counter bore the through hole until the sight fits over the sight bead.
If the joint fails I will replace the sight bead with a 5-40 button head allen bolt.
The next step is to remove the finish where the LPA sight will be bonded to the barrel
Even though I will refinish the gun I want to remove the least amount of the factory finish. I mask the area with duct tape and bead blast the finish in the area that the sight will be bonded to.
I also bead blasted the front sight, the you can see a difference in the finish of the two sights, the
Once it has been cleaned follow these steps to bond the sight to the barrel.
- Re-tape the barrel
- Apply an even coat of JB Weld to the underside of the sight
- Apply some JB Weld to the bead on the shot gun
- Set the Front sight and place and use a clear tape to secure it in a level position
- Wait about 1 hour (test the left over JB Weld for hardness) and remove the excess with a popsicle
- stick which should create a nice fillet at the base of the sight.
- Remove the tape and use your finger dipped in alcohol to smooth the fillet.
- Re-apply new clear tape to the sight, verify it is still level and re-secure the front sight
- Let it cure over night
To Be Continued Tomorrow