Super Simple Limited Use Masonry Tools

A simple pair of masonry tools primarily intended for making small repairs to brickwork, such as re-pointing: 

• Trowel - for applying and adjusting the mortar. If re-pointing, this tool may be all you need. Use it to introduce the mortar into the gap and smooth it out.
• Jointer - for giving re-pointed mortar that neat, concave appearance expected on visible brickwork. The shape provides a smooth barrel by tapering at each end, reducing the risk of dragging mortar.

These are intentionally simple and do not replace actual tools - they are simply for those (like me) who have a small job to do and don't want to spend on tools they won't use again for a long time.

Printing:

• Filament - I use PLA. I don't think it matters much, though remember that mortar (like other concrete mixes) is exothermic when setting, so it is possible it will be warm enough to damage PLA if you're working with it for long enough.
• Supports - the shape of the tools requires supports. I positioned the tools so that I had to support the trowel handle and the top of the jointer barrel (i.e., the flat part). In case my description is unhelpful, I included an image of the supports in place. I like snug with 2.5mm z contact distance, rectilinear grid pattern, and heavy top interface layers. They eventually come away (with some persuasive violence) relatively cleanly from these simple surfaces.
• Infill - these are tools, but not particularly stressed by the work they're doing. I went with 40% gyroid. I suspect that you could go as low as 20% with gyroid and be just fine. Gyroid is my preferred infill when I am not confident in the directional forces that the object will experience.
• Sizing - In PrusaSlicer, I extended the width and length (but not the height) to 125% for my hands, which are fairly average male hands. I was able to fit both on the Sovol SV06 bed. If in doubt about what I mean, my sizing was X: 125%, Y: 125%, and Z: 100%
• Brim - I used a brim only because the handle surface on the jointing tool was small relative to the height of the object. I wanted to avoid the risk of it wobbling before it reached the supports, so a 5mm brim was added.
• Post-print processing - Any supported surface can be rough and the rounded sections might be rough, depending on layer height. A little sanding can help - you just need smooth-ish, not smooth. Any surface contacting the mortar will eventually fill in the roughness through use. Avoid supporting the working surfaces to minimize unintended imperfections.

If you make use of these tools, please know I am not a mason, nor an engineer. These tools are not a direct substitute for commercial tools and should be treated the same way you would treat a 3d-printed drill bit - they look the part, they might even work, but eventually they will fail you. 

Before undertaking any home improvement or repair, be sure you know what you are doing and that you know the root cause of the issue (i.e., don't fix symptoms of a bigger problem until you've fixed the bigger problem). Bricks can need re-pointing due to age, weather, or poor materials in the original construction - the same symptoms can be see when a structure is experiencing subsidence, pressure from soil due to poor drainage, limited expansion options for large walls, and a long list of other reasons that only a qualified engineer can help you diagnose. If in doubt, hire a professional engineer to help you understand the problem and if this fun little trowel and jointer are going to be sufficient to resolve it. It might be expensive to hire someone, but I promise you they are cheaper than fixing a collapsed wall in the future.