Reinforced cross drilled block

A method for assembling at least a portion of a heat exchanger that includes a graphite block and graphite tubes, the method comprising:

• receiving a graphite tube that includes a coating on an exterior surface of the graphite tube;
• receiving a graphite block that includes an aperture extending through the graphite block;
• positioning the graphite tube at least partially within the aperture of the graphite block such that the coating abuts an interior surface of the graphite block that at least partially defines the aperture;
• and
• performing an impregnation process on the graphite block to force a resin into at least some pores of the graphite block.

A system comprising:

• a graphite block comprising (i) pores that are impregnated with a resin and (ii) process apertures extending through the graphite block;
• tubes at least partially disposed within the process apertures of the graphite block, the tubes comprising a cured coating disposed over curved exterior surfaces of the tubes;
• and
• a graphite cap disposed over a portion of the tubes at an end of the graphite block, the graphite cap comprising openings, wherein at least one opening of the openings includes the cured coating and the cured coating seals an area between the graphite cap and at least one tube of the tubes.