VCCA Home Forums TECHNICAL - GENERAL Upholstery - Interiors & Glass Windshield Sealant

The Assembly Manual for Advanced Design trucks states that GM #3686628 sealant should be used between the windshield glass and the weather strip as well as between the weather strip and the body.

The '48 - '51 truck shop manual simply states use 3M weather strip adhesive in both locations.

What is today's equivalent of those sealants? Is it an application for a hardening or non-hardening sealant/adhesive?

Checking older posts I see that some people use the 3M Black Super Weather Strip Adhesive. However the 3M specs on that specify it is for bonding rubber to metal. Will it seal to glass?

I also see that there is a 3M product auto bedding and glazing compound that is intended to seal weather strip to an auto body. It is a non-hardening sealer.

Thanks for the help!

This is what Steele recommends. https://www.steelerubber.com/glazing-compound-96-8509-96

That is the proper product to use with a gasket windshield, weather strip adheasive is just that an adheasive and not a sealant

Thank you for the confirmation.

I can understand using adhesive to attach weather stripping to doors and trunks lids. It did seem odd to use it for the windshield.

I agree that this is really an application for flexible sealer. You are not bonding the weather strip to the metal. You are dealing with 3 different materials in this area: glass, rubber, and metal< They all expand and contract at different rates plus the body flexes as you drive the vehicle.

I have used 3M Auto Bedding and Glazing compound for many years. Has worked for me.

Thanks Chipper!

NAPA will have it for me tomorrow morning. It is 3M 8509.

You are going to need to get it warm to apply and use a good caulking gun, it can be pretty tough to get a good bead out of the tube. Have some prep-sol handy and some clean rags it can get messy, at least it did for me

I would like to add to this discussion that whatever is used it may be best to apply it after the glass is installed. You have a pretty big mess on your car and hands if you apply the sealer etc. before installing the glass. It is also easier to do the work without the dash, engine, fenders, hood, and headliner installed.

Mike

Thanks for all the inputs. We installed the windshield in about an hour yesterday. The work went smoothly and it was not near as messy as I anticipated.

The shop temperature was in the mid-60's so the bedding compound flowed out of the caulking gun nicely. We put a fairly heavy bead on the seal where is seats against the outside edge of the pinch weld. There were a few places where a little excess squeezed out.

We are going to wait for warmer weather to put a hardening sealer between the outside edge of the glass and the rubber.