Our end goal is to mud over the existing plaster walls/texture to create a smooth finish. Before this we want to repair several hairline cracks to prevent them from recurring. After scraping open the hairline crack we plan to add caulk inside the new, wider crack, but not fill the space all the way to the surface, leaving room for a sandable Durabond to bring it flush to the surface. Our thinking is that the caulk would allow for flexibility at the back of the crack and the Durabond would allow for better control of the surface sanding process. We would appreciate any insight into this process.
I have worked on several high end homes with plaster walls over the years along with many hair line crack. I'm an expert drywall finisher with 30 years under my belt so for best results I would contact your local drywall company. Remember - Drywall Finishing is an art - it is not something you can pick up as a DIY and expect expert results. But my personal success on the question is as follows.
- Open hairline crack by scraping with razor knife 45 angle
- Sponge or wet rag over crack to remove plaster dust
- Use mesh or fiberglass tape with either durabond or USG All Purpose (GREEN CAN)
- Build out taped areas as a but joint
- Sand entire area knocking down any sand texture or multiple layers of paint.
- I top with 2 coats- 1 USG Green all purpose followed by 1 USG Lightweight Blue can. I hope this helps